This hand threw me a bit as I was having trouble reading this guy because this is his 1st hand and he posted in the CO.

Boss 5-max, NL 150

CO villian has 150, BB has 100, hero covers.

CO posts, folded to the CO who min raises to 3, hero calls OTB with [8d], SB folds, BB calls.

Flop [Ac][2d] pot is ~10$,

BB checks, CO bets 7.50, hero just calls, SB folds

Turn pot is ~25 $

CO bets 22.50$, hero decides to just call (potentially a mistake thoughts?)

River pot is ~70

Co bets 20, hero ponders how much he should raise here.

Surprising as it may sound, I think the big mistake is not 3-betting preflop.