What affiliate marketing is all about is selling products that you did not have to make yourself. Instead you can just sell others products and get a commission for everyone you refer.
Some people make a great living from home. Even fewer make millions. But how much you want to make really depends on how far you want to go.
As a beginner you must learn affiliate marketing basics. You should start by signing up to an affiliate network like Clickbank or Commission Junction. Clickbank is one of the best places to start because of how fast and easy they make it.