Well in RPG Survival you basically just do normal survival stuff. Like what you would do on a single player survival world. Except you have other players of course lol, but you also try and level up you're skill in different things like farming, mining, combat, or what ever is off the righ on you're screen. You also try and make money, you can do so by making a farm, mining and selling things like iron and gold (or what ever you mine in a cave of value xD).
So yeah you pretty much just do survival things like build a house, make money, and have fun