You have to be technically sound. Apart from that you have to have a good aesthetic sense. A sense of style is imperative for a good photographer. It is the photographer who dresses up the model. So unless you have style the models you dress up are going to look bad. You also have to be down to earth and not high-headed. Buy a professional camera and get the technique right - understand basics like film speed, etc. You can even learn through books or surf the net. I shot a lot of films during my training phase.
Get a personal portfolio of your pictures ready and show it to ad agencies and magazines. You have to convince them to give you work. Otherwise, why would they take a chance with a newcomer? For that, you have to create your own personal style. You have to have your own style. Do not imitate your mentor. Initially it's going to be difficult but you have to keep the spirit.