Most important thing is having fun, but you need to focus on the following to do that.

1) Good Riding gear. If you get hurt your no longer having fun.

2) Safe sound reliable motorcycle. If the bike breaks you're no longer having fun.

3) Learn everything you can from a reliable source off the track. Get as much seat time and instruction on the track as well. If you don't know what your doing it becomes stressful not fun.

4) Make friends with others in the MRA who have been there and understand whats going on. Being apart of the MRA is more than just racing its a family atmosphere who you'll likely gain lifetime friendships with and without that support system I would not have made it without all of them. Not to mention not have had nearly as much fun.