On the preflop SB 3-bet quite big, so it usually means he has very strong range, I think it will not be mistake to fold. But, A8s is near top of your range, so call is not mistake too.
On the flop, you can't have JJ, because you would 4-bet them pre, and you also can't really have 33 or 44, so you dont have sets that you can rep for value raise. That means if you don't have value raise, then you shouldn't have bluffs neither. On the flop call or fold, don't raise with anything. With A8s it's clear call, you can be ahead here a lot of the time against K highs and Q highs and also have nut flush draw.
On the turn, once SB checks, you should definitely check back, and the main reason for that is that you already beat a lot of his K high and Q high
hands that SB has, so you have decent showdown value. You can
bluff with some of your worse flushdraws, that don't have showdown value. Also it sucks to bet and face raise with this hand, as you want to realize your
equity. As played though, I definitely would call allin here, because you have flushdraw and straight draw. 17$ in the pot already and you just need to call 7$. You need 29% equity, and I think you have it.