AQo

PF: standard.
Flop: I preffer to bet bigger. there are 2 on the board and a GS for A2/A4. Think I'd go for 3/4+
Turn: You look more interested in keeping weakest hands- thus risking not extracting value if he chbh, and risking him hitting better than you - than you look to take value and protect your hand - any :club:, K, 2, 4 can be a bad card for you. 1/2 to 3/4 would be my bet. If he folds smaller pair, the hand was done and I'd take the small profit.
River: River is when I usually go for smaller bet (1/3 to 1/2), if played bet-bet. As played, you decided to call with your turn action, if villain has a 3 it is a consequence of you not betting the turn, most of the times, any other hands don't change, from your turn decision to call.

Against a unknown on NL2 I would Cbet all streets to get it in on the river. Board is draw heavy and your hand needs protection. It's not likely villain will bluff to often, but that's villain depended.

Cheers,
SDK1987

Bet bet bet, villain is unknown, so we don't know his bluff tendencies. As played calling down.

There's a lot of value here:
KcTc, KcJc,
KhQh, KcQc
KdQh, KdQc, KhQc, KsQh, KsQc, KcQh
QcJc, QhJh
QhTh, QcTc
9c8c, 9cTc, JcTc

I think should bet too on turn and maybe recover some of stack, he catch unlucky for me set of jacks on turn.