What to do in a long play session?

Hey there fellow Vaultdwellers. I'll be playing a ton of 76 for an upcoming charity event, and I was drawing a blank on what are some things to do during a longer play session. Like, normally I only have time to do dailies, a few events, maybe a daily op before I have to stop playing on a weeknight. Since I have way more time as part of this event, I wanted to put together a list of things I should work on now that I'll have the time. Things like major quest lines or possum badges or unlocks that take more time than normal. I've already decided I want to learn expeditions as one example. What are some suggestions for a longer play session?