You decide your job role and you decide what you are comfortable with. As your confidence grows and you become more familiar with the different tastes of clients then you can then start to earn even more money.
So how much money can you expect to make? This is a trick question. It all depends on how often you are online. The name of the game is building a fan base and having regular customers means working a regular schedule. Average models that do a set 4-6 hours per day/night average roughly £150 - £250 per day/night.
So how much money you can make depends on your consistency and the efforts that you put in to give a great online show.