To obtain food, go exploring and hunt prey. Predators only drop mush and occasional relics (animal hair, sun bear skin, etc) while prey drops food and mush, and sometimes relics ([animal] skin, etc).

You can earn mush by exploring, playing mini-games (Realm < Games), hosting auctions, selling things (to Market Den or Montak), selling wolves (or breedings to them), placing top 25 in the FMC, etc. You could also sell your artwork (game currency only) if you’re an artist.

Edit: Reformatted the paragraph into two parts.