First: you should just call A4s pre BB vs MP. You really aren't doing it for value, because there aren't that many hands that you are way ahead. In the best case scenerio you are like 65% favorite, and because you are OOP you will realise less equity. There is an argument, that you will have a range advantage, but still I would prefer the call. Especially versus 2bb open.

As played

I think flop and turn plays are fine. You might make an argument for betting turn little bit bigger, since 8 will improve villain's range quite a bit, but still, it's not bad.

On the river, I'm torn between c/c and c/f here. He might be value betting some Kx and Qx flushes here, thinking that you have over pair or something. But on the other hand villain has a lot of boats here. I think you should type into the equilab what do you think he has once he bets after you check, and then see what equity do you have.

I rly doubt if overpair calls here. So I x/f

Pre prefer flat

Flop/turn fine, though you can size up turn oop imo

River pry check whole range

Can't see too much 7x in villain's range, probably 67s, 78s, maybe 97s and A7s. Could also have 88 and AJs, KJs, QJs, JTs. Maybe AJo and KJo too, not really sure.

Hard to know because if it's first hand against him, even if the open sizing tend towards a recretional player. That seems really surreal to gave him such a wide range without reads.

But he could also have 99- AA and I doubt he folds them to a shove.

All these hand are folding the river without a doubt.

He might be value betting some Kx and Qx flushes here, thinking that you have over pair or something.

XF to me. Most of villains (regs or fish) will be happy to XB their Khi and Qhi flush when seeing two pairs on the board.
If we assume he's a fish, I think there is too many Jx to consider anything else than XF.

Interesting hand. I would also call pre btw. On the river I would bet-fold something like between 1/3 - 1/2 of the pot. We can still get some value from QQ, from lower flush and from 9Ts. But it is really thin though. But I am not sure how thin this is. Maybe going for check-call somewhat small bet and check-fold against higher sizing is better.