I'm going to firstly tell you about kid pokerstars small balls strategy which is pretty much bet half pot heads up against 1 opponent on any board since they are likely to have missed it. Let's give an example

I had aq opin the cut of raise 3x and the big blind calls. Flop 449 he checks. Daniel would say bet. However the thing is ace high is probably the best hand and the other thing is if he bets he may be missing value from the opponent bluffing on later streets. The problem is he needs a read. Another thing the opponent is unknown, no history with them. No tells nothing. So betting is safer right? However it means -EV. plus you may hit the turn or river and if he has kq he could lost alot or a2-aj whatever. So

So what's the right play? And if the right play is bet than when is it justifiable to check? When your opponent is aggressive? What if the opponent is aggressive but you don have a read? How much information do you need to check behind?