Polls are kinda boring right now, not much change going on. The battleground states are what we need to be watching, but as of now, Trump is leading in all of them and has been for a while. These states will decide the election.
Possible candidate swaps or a major news break is what could change things, but not much way to predict those right now. I fully expect some kind of "October Surprise"; the question is, from which side. My guess is, one that will hurt Biden. I'm not sure there's much else that could come out about Trump, or that it would change anyone's mind if it did.
I also think the economy could be a game changer. If it does take a dump, as many are predicting, that will likely hurt Biden.