Tips for first time at gorge?

Me and my girlfriend are planning a trip to the gorge near the end of September. I just want to know if their is anything I need to know. Planning on getting a backcountry pass unless that's a bad idea for a first time visitor. Also are their any good fishing spots near or slightly off of trails? I've heard there's an upper gorge and lower gorge; what would you ladies and gents recommend for a couple of first timers?