Hey. As part of my learning proccess, and to help more beginner players here, I will be posting hand histories of mine with an analysis that I write afterwards,
So hopefully the more experienced players can share their opinions on the hand and the analysis.
Thanks to everyone who can help :)

Hero (BB): 116.5 BB
UTG: 77.5 BB (huge whale)
CO: 111 BB
BTN: 121 BB
SB: 108.5 BB

SB posts SB 0.5 BB, Hero posts BB 1 BB

Pre Flop: (pot: 1.5 BB) Hero has 9c 9h
UTG calls 1 BB, fold, BTN raises to 3.5 BB, fold, Hero calls 2.5 BB, UTG calls 2.5 BB

MY PREFLOP ANALYSIS:
UTG is a whale (80/15 something like that) so my first thought is that we want this guy in the pot so flatting here is good. But:
- we are oop to both button and utg, so we will have to fold an enormous amount of flops.
- BB is a fit or fold fish, so even if we do hit a set chances are he is gonna fold and our implied odds don’t matter.
So 3betting here is probably a better option.

Flop : (11 BB, 3 players) 6h 3d 3s
Hero checks, UTG checks, BTN bets 3 BB, Hero calls 3 BB, UTG calls 3 BB

MY FLOP ANALYSIS:
Me and the whale check and button bets extremely small. We are obviously not going anywhere - calling is optimal.

Turn : (20 BB, 3 players) 4c
Hero checks, UTG bets 10 BB, fold, Hero calls 10 BB

MY TURN ANALYSIS: Here is when things get tricky, the fit or fold whale donks half pot, and button folds.
We need to ask: knowing this type of passive player probably doesn't bluff this spot too much, but since he’s still a fish we can assume that he has tons of 6x, 5x, Ax, and 77-88 that might bet the turn, we are still not going anywhere and a call here is probably the right play.

River : (40 BB, 2 players) Kd
Hero checks, UTG bets 20 BB, Hero calls 20 BB

MY RIVER ANALYSIS: river is a mistake imo, since we know this kind of player under bluffs we can expect to lose here a huge amount of the time, I dont think he donks into 2 players and than barrels again with worse hands.
I should fold here.