AKo

Not sure if you have any info on him, but I don't think it's bad to make a thin value shove on the river against a random NL2 player. Off course you could lose sometimes against a set, but I wouldn't be surprised he would play QQ+ more aggressive pre-flop and you block KK+ here.

Cheers,
SDK1987

This is a pretty straight-forward hand.
You have a easy shove when you improve to 2 pair OTR. SPR is already < 1, so no point in checking back.
KQ and AQ are your target hands. QQ should raise OTT mostly, KQ maybe.
33 shouldn't be calling 3bets OOP from UTG, but probably a fish does call.

Notice that on this runout, triple check/calling with 77 is a very well played (he can't fold 77 when triple check/calling or he will be exploited).
On the other hand, calling a double barrel with a hand like J♠:T♠: is probably ok with your turn size.
Shoving OTR is certainly + EV. If he has 77 or JT that's life.
I would probably bet smaller OTF and size up a bit OTT too.

but what hand did he had

I would shove the river for value.

Same thing as the other hand i commented 2 seconds ago: the line here is correct, the sizing is a mess. You bet too big otf, when you don't need to. It brings you to bet too small on the turn. Plan the hand with the idea of having more or less the same sizing % on the turn and the river. If it's not possible, it means you need to play it in 2 street. Here it's well possible, just rethink you sizing from the flop.