I am trying to give you advice that you would do well to heed. That is to study the subject properly. Google is your friend.
You can't expect to learn a complicated and involved skill or profession and set up in business (I'm not just talking about this thread, but your other threads as well) just by asking for one-line morsels of information on an internet forum.
You need to do it properly and get some serious research done. Study the work of well established and respected photographers, read, read, read, practice, practice, practice.
You're not the only one who's ever started from nothing.