Wanting to be a photographer, need tips?

So, recently i've devised a plan that i'd like to try out some photography. I plan on getting a nikon d5100 to start out with. I think it's a good plan due to my gramps is an artist and he could sell my work at his shows + we know a photographer in new york who is very close with us and has made milllion's already from it… So basically just some tips and let me hear about how much you love your job or hobbie. And yes i realize it can get expensive for camera's, tripods, lenses etc…

Added (1). Well everyone i see one answer that gives a good idea of the answer, and everyone yes my gramps sells his art so i know i could probably have him sell my art with his or hell get me a booth and the person from new york can help sponsor some of the art but i'm looking for several opinions of photographers and what its like for you out there who does the photography.

You have a grampa who's an artist and a friend of his who's a millionaire photographer and yet you come to us for tips? Gosh! Organize a tea party, invite those two geezers to talk and we'll all come in and listen.

Why do you come to us if you have a gramps who is a artise or whatever you say he is? I really dislike people like you.

As a career you will need stamina and determination and the ability to re-invent your style of work quite often.

Have you asked your gramps if he is willing to sell your work at his shows?