I want to know (you are on your own)means you are what?
It is pretty good.Is pretty the same as very or more\less than it,Which one?
'You are on your own' = you must make the decision/do the work/solve the problem yourself, with no help from others (or at least from the speaker).
'Pretty' = rather, somewhat. It is an intensifier: things can be pretty good or pretty bad.