what i mean is train everyday like its ur last, or your last fight or like everyfight is the most imporant fight for you, then being the best will come if you are inf act the best, or it wont and maybe you will be good, or maybe you will find out its not for you.
Pick your styles and start training, as you go you can ask more "specific" questions, but thats the best asnwer i can give to the "be the best" question.
Find people to roll with. Learn some submissions, but more importantly learn good positioning. Being in the right position is one of the best things to learn right away. Learn to pass gaurds and half guards. Learn some good defense...
What I find when training... what you want to work on the least, is what you need to work on the most. I like throws and submissions, not much of a striker. So I need to spend more time on my strikes because you favor what you're good at.
Hope this helps out a bit, don't go rushing into fights, and don't do it for the bragging rights.