I "crush" my local games for $13/hr with buyins ranging from $30 to $75 and entrants between ~9-40 players. To give you my background, I've played about 5 million hands of zoom poker and heaps of sitngo's before zoom took over. I studied sitngos for about 2 years before swapping to cash.
For live-tells stuff I watched all of "reading poker tells" youtube vids, read the posts here now and then, and read Mike Caros book of tells. I use a bit of white magic too. Just look at someone and you can tell if they're relaxed/confident or stressed/scared (I don't put too much weight on tells, but if it's close between decisions it can help).
For overall playing advice my overall strategy is to play super-tight early, develop an image of being someone who is scared to play hands, and then shove wide late in the tournament now that you've gained respect. I've had players show me AK when they folded to my shove for like 8bbs.
Every time I enter a pot I raise. Zero limping first in. Sometimes I might limp behind early in the night with PP's or suited connectors if I'm in late position and I know the blinds don't raise without premiums. Early on with 150bb+ I raise to 4bbs. When I have 100bbs I raise to 3bbs. At about 30bbs I raise 2.5x and with 20bbs I raise to 2x. It's push or fold with about 12bbs and less. If someone else raises I almost never call behind. I always 3bet or fold unless the person is also a nit like me. If I'm committing more than 1/3 of my stack pre flop by 3betting I just shove all in. I do this with all hands including KK+, I don't try and get tricky and do a min-reraise or something weird.
Player types are important. Whenever you are not in a hand (which is a lot) I watch the players for betting styles/sizing, how often they call compared to how often they raise etc. I then use that information for how to play against them post flop. Bet bet bet vs calling stations. x/c x/c x/shove vs maniacs etc.
Generally I only cbet heads up on J+ hi flops. They always put me on strong hands because I play so tight and respect is key. If it's T hi or below I check. Then if a card higher than T appears I bet the turn, if not, I check back. It's not always this simple but that's the base-line strategy. If I have a strong hand, I do not slow play almost ever, I aim to get the money in with big bets.
The weird thing is how much they fold to all ins yet call big bets.
Most important is to not go down in chips early because we need fold equity. Any marginal spots, just fold. No need to chase. We need an average, or just below average stack when we hit the 20bb mark and below. We need to use our fold equity. I shove 100% of the time Sb v Bb with 10bb and below (depending on the player, but against almost all players I will do this). I fold my SB a lot and the players have a go at me for being overly tight. They always want family pots. I only ever push or fold with below 12bbs.
As for actual starting hands I can't put all that in here because it changes with stack size, position, ICM, and player types. There's probably heaps more to say but hopefully this helps. Everyone plays different but i would say never show your hands, not even one card. Try and remove the LAG image, even the TAG image, and get a NIT image. Stay in the background watching the other players and only come in to a pot when you are strong.
Hope this helps. Online can be pretty tough. Live games are easy. Try and run good too
Oh and also, try playing 45 man sit n gos online and find a strategy that wins there. You will find it also wins playing live.