I'm new to poker and keen to learn so any advice on this hand would be appreciated!

I was playing a pub poker tournament last night. Starting stack is 300BB but within 1 hour you're down to 30BB (if you maintain your start stack)

I was on the Button with KJs. All players in this hand started the hand with around 75BB. EP weak player makes it 3x. I call, BB calls. Flop is 3h3dKh. BB checks, EP raiser bets 2K into 3.8K. I call, BB fold. Turn Ac. EP bets 2K into 7.8K I call. River is Qs. EP bets 2K into 11.8K I call. He shows Ah6h.

He was playing way too many hands and "value-betting" mid pair and tpwk hands on previous rivers. I put him on 0 bluffs for this river but thought he would definitely bet a King, possibly a queen and maybe even 88-JJ. However, I felt like he had a King. In past hands when he made a stronger hand on the river he would suddenly overbet the pot, whereas this time he maintained his 2K bet sizing throughout. As such, I think I should have folded the river because I was calling 2K to win 6K (50% of the pot) about 2/3 of the time and probably losing the other 1/3 of the time.

Another consideration I had is if I should have raised the flop. I think he calls with every flush draw, every weaker King and probably 77+ based on how he'd played previous hands (though I'd only been watching him for 45 minutes at this point). I called for pot control with a view to betting big on later streets if I had a favourable run out knowing he would call with worse.

Any thoughts and advice would be greatly appreciated!

Preflop - Fold. Hand does not play well against EPs range.

Flop - Call. If villain is going to make big mistakes if you raise then raising is of course good but most of the time when you raise better hands than yours will call and worst hands will fold.

Turn - Meh. Is this guy really going to be betting a hand like TT here? That is what he needs to have for you to call. Chances of him having a flush draw that doesn't beat is low. If he has the AXh you are crushed. He cant have Kh because it is on the flop. So he has to have something like QJs or worse which may might not play (or just open limp with).

River - Same situation as the turn. Is he really betting TT two streets in a row with a K and A on the board? Is he doing this with KQ where we chop? Even if so there are not a lot of combinations with a K given half of them are in our hand/on the board. But we do not need to win or chop very often to make the call profitable...

If you are correct that you would chop 2/3rds of the time on the river it is an easy call. Even if you were 0% win, 1/3 chop, 2/3 lose the call is profitable.

Crazy structure .. very hard to pass up KQ and/or know what a Player's range really is when the Blinds come after you so hard.

If you are new to poker then how do you know that this Player is weak?

Based on your description you know the Player has 'something' and probably not a 3x since they would probably bet more on the Turn .. and really not a lone Qx IMO either on the River. You probably don't see a Turn bet unless an Ace or King is involved. Unless you have a really bad image there's very little expectation of a lower PP IMO with a paired Board and two over-cards.

Raise Flop? Possibly to get HU but you are OTB with a pretty strong hand .. better to wait and bet the Turn if it checks to you and allow this Player to keep bluffing. But you don't mention bluffs, you only mention they will bet with mid-pair and other 'value' spots. So you flat Flop and if they bet Turn then you know you're in for a chop or losing to an Ax.

River .. Does he know he's chopping all his Kx holdings and he still bets? Again, what does he put you on, if anything?
River .. Does he know how valuable those 3s are on the Flop? And yet he still bets only 2000 .. Is that a consistent betting pattern when there's 'danger' on the Board?

IMO pretty standard River spot and you're getting a good price. No sense in raising unless you can truly 'sell' that you have a 3x. (Not likely)

Pre-Flop .. KQ is pretty damn strong in a Turbo and you may want to consider a 3b to hopefully get HU and take the betting lead. How often will this guy fold if he misses the Flop? Against a splashy Player you should be well ahead of his opening range.

Usually weak in poker means passive and that's not what we see here. They may be weak in understanding, but I'm just not buying that they don't realize a paired Board and two overs is not good for everything else on the Turn. So we must accept that it is what it is .. and Ace or King and we're getting a good price. GL

Thanks for the reply, I appreciate it and it gave me some things to think about