the plant monsters kill me and add influence, and there seems to be no way to just return to hub. this seems hopeless...Skip all of the enemies in the starting area, you're guaranteed to lose any fight against the slime witches and they're placed so you can safely just walk to the exit.
Once you get to the main hub you'll get a weapon and can actually kill enemies. If you need to you can just walk to the chests, open them for quick money and equipment, and then exit the dungeon and go to the shop to buy gear.