So ive been doing a bunch of minor side quests in effort of being fully prepared for an expedition, because i have no idea what to expect of me. I haven't run any, so can someone give me idea of what to expect?

Is it gonna be a lot of fighting? Resource gathering? Star skipping? Should I go in fully loaded down with stuff or empty pocketed? I'm thinking of starting them this coming week, and trying to earn some of the specific upgrades you only get from them, is a week enough time?