What do you prefer to play against 1.e4? 1. ... e5 or 1. ... c5? What are the advantages of each move?
Can they becobmbined in a repertoire?

a) c5

b) I avoid all 1...e5 theory and can dictate (to some degree) which flavor of Sicilian I want to go into (which hopefully I am more familiar with than white).

c) Of course. Professionals are pretty familiar with all major openings and what you're playing becomes very player-specific. E.g. If you never play 1...c5 then you may miss out on a bunch of potential lines your opponent may be weaker in. This consideration doesn't really matter at all for club-level players since there often is no time or way to prepare for specific opponents and/or you don't play the same people much. Plus, it's likely more worthwhile to work on other aspects of the game than having a repertoire that involves too many major responses.

thanks for the answer! A 2030 FIDE rated player told me on the contrary
that 1...e5 is better for club players because
a) open games are basic for general chess knowledge,

b) there is no opening you actually fear and in most you gain equality and

c) Sicilian positions are tough to play if you dont have certain chess skil and experience

I also want to choose one of either the Slav or the Semi-Slav against 1.d4 and want ot read about it.

Which one do you believe is best to start with?(ideally I want to play both)

Ultimately they're both perfectly fine moves. Which you prefer is going to be a matter of personal preference, there's not an objective truth to which one must be played (and there are other perfectly fine responses as well.)

It depends on a lot of factors of course. One is your playing strength and level of knowledge. At the high end of the spectrum, professional players can and must be comfortable with either, or else they will become too easy to prepare for. There are a few exceptions, people who carefully specialize in just one opening and dare their opponents to beat them in it, but most pros have a relatively diverse repertoire to keep their opponents off guard at least a little. They may play one most of the time, but probably not always.

Below the master/professional level, none of that matters much. As a club player you're probably not going to see too many people actively preparing to face you by studying your preferred lines, and anyone who DOES attempt it probably won't benefit much from the process as "how to properly prepare an opening for a specific opponent" is a skill most club players haven't learned.

1. ... e5 is classically recommended for beginners, because it (can) lead to open positions in which you will have more opportunity to get first-hand exposure to lots of tactical motifs, which is a hugely important learning device for new players. This is what the expert you spoke to was talking about with point (a). However 1. ... e5 doesn't have to be followed in the 19th century romantic styles, and the most common 1. e4 e5 lines in GM play are actually very positional and strategic, which is also great for learning... but more nuanced and probably less ideal for a raw beginner. So it's fine to play 1. ... e5, and if you're a beginner you'll probably see a lot of Italian and Fried Liver/Evan's Gambit stuff that will be a lot of fun (if you enjoy that swashbuckling style) and definitely educational for tactics. By no means is it required though.

Regarding point (b): I think that has very little bearing on beginner or club level players. The term "equality" is important in master level opening analysis, but only comes into play if both players are strong enough to play with sufficient precision in the middle game. For club players it's a lot more important to enter the middle game with a position you understand, and are comfortable with, and can find plans in, than with objective equality. I'd much rather, at the 1500 level, with black, be in a position I understand where the computer has me at -0.5, especially if my opponent isn't familiar with the strategic ideas, than to have equality (0.0 comp eval) but no idea what to do next. At that level players will blunder half a pawn (or sometimes much more) multiple times per game. If comfort with, and understanding of, your position can prevent even one of these blunders, then it's immediately worth more than equality is.

As for openings you "fear", I think for precisely the reasons above that's a different list at the club level than for more advanced players. Club players should absolutely fear, for example, the king's gambit, if they have not yet familiarized themselves with it. It's seldom played at the top level, because for masters it allows equality (or more) pretty easily for black, but it is also chock full of potentially catastrophic pitfalls and you can lose very quickly with one wrong move. A king's gambit "specialist" is a very dangerous opponent at the club level. That said, I don't like the phrasing too much, because really at the club level I would advise you not to fear any opening. The worst that could happen is you might go wrong and lose the game, but as an inexperienced player looking to improve that's not actually bad! You WILL lose tons of games, but there's lots to learn from it. It's in your best interest to see lots of different openings, lots of different pawn structures, lots of different tactical motifs, lots of everything. It will give you broader learning opportunities, and if you take advantage of that and study your games afterwards, it will help you improve much more rapidly in the long run.

As for (c): Chess is a very complex game. All positions are tough to play without certain skill and experience. That's why it's fun! As long as you're playing opponents who are at a similar level to yourself, seeking out "tough" positions is fine, because it will be tough on your opponents as well!

So which should you play? I don't know. I prefer 1. ... e5 for purely personal reasons, but have no interest in trying to advocate it for you. If you play a lot of chess, and plan to study actively with the intent to improve, you should probably try both, play a bunch of games with both, lose a bunch of games with both, get a sense of the kinds of positions each leads to, and decide based on that. If you're a more casual player who just plays occasionally for fun, and doesn't want to study so seriously, then probably just pick one out of a hat and go with it. You can always come back and try the other one later if you want to. There won't be a "right" answer, without a lot more information that you probably need a lot more chess experience to give us.

I'm not 2030 FIDE but my response to that is "Meh." I don't necessarily strongly disagree with any of it but the conclusion that your repertoire should for sure be based on 1...e5 instead of 1...c5 just seems silly.

I mean, even as a beginner if you want your repertoire to revolve around the English and some sort of hedgehog stuff it's fine too. It's probably a good idea to get some exposure to other openings at least through looking at games that involve them (e.g. don't just never study 1.e4 e5 games simply b/c you play 1. d4 and 1...c5).

I don't even know the difference between those. For some reason I assume semislav is just some variant of the slav proper? I don't play them (super obviously) and could only somewhat confidently point out what a slav position is. I can't imagine it matters almost at all which you choose. Since you say you'd like to play both, just flip a coin, start with that and then add the other.

I agree with The Yugoslavian that we don't need separate threads for these two repertoire questions, so I merged the threads (and edited a few posts to maintain clarity of which of the two questions was being asked, or responded to).

thx for the detailed reply bobojoejim!
any thoughts on the slav vs semislav choice?

This is very easy to figure out on your own:

Step 1) find a coin
Step 2) assign one side to slav one side to semi-slav
Step 3) flip the coin
Step 4) ????
Step 5) profit

I am little concerned with the classical slav cause it gives white
the central majority... I suppose that black shall play very accurately
to maintain the balance (yugo we have to accept flips in poker
cant do it in chess )
😛

Sounds like you've decided to look into the semi-slav first, congrats!

This is for club purposes, tournaments can show different results: I would play into whatever position you want to see in game. If you know someone that loves to play giuoco piano/2 knights defense, ruy lopez, four knights defense, king's gambit, etc, then you must decide if you want to play in that position in game. Meanwhile if they play something like Sicilian Open, closed, grand prix, smith morra, etc. then you might choose c5. Play what you want to see the position turn into after the opening, not the other way around.

I'm honestly a person that will just throw a random pawn forward during the game (more often g6, c5 than others) so I can get variety and learn about the different plays you can make in a game.

Thnx onuzq! For club purposes your advice is best and im trying to
build a repertoire for tournaments