Assuming you are talking about the mainstem, I would definitely think about getting a guide and floating. There isn't a ton of great wade access despite the river being public once you get on it. Its been awhile since i've gotten a guide there but last time I did i fished with Lee Hartman and he was good. You could also check the Delaware River Club. I've never fished with the guides but I've been in the fly shop a bunch and they have always been helpful. There can be decent iso fishing in September as well as streamer fishing especially if the water comes up a bit.
I'm honestly not a big fan of the west branch but plenty of people consider it the best water on the system. I prefer the upper east. Lower east can also be good but you really need to know the spots. If you just have a day or two it can be a tough go.