I'm new at all this, so some questions might have extremely obvious answers to everyone else.
We're all new at some point !! Glad to help you out.
1 — How do I give Prey Points to other members, and how can I get more? What's PP used for anyways?
A: You go to the Shop, and to the left you'll see an option to allow you to send PP to others. It's used for purchasing things from other people or purchasing TCG from the shop via “Buy Stuff”.
2 — How do I get cards for the TCG, and what do I do after getting them?
A: See above! The aim is to just collect as many as possible. Collecting sets allows you to earn freshkill points (different than PP) for your Clan/Tribe.
3 — Can I edit a draft without posting it?
A: I believe so!
4 — How do you ping other members?
A: Just use @ (membername). I can go [member=127]finchthewyrmling[/member] to ping you. It'll show up in your mentions.
5 — Is reputation important?
A: There are some feather rewards for getting high rep, but otherwise, not really.