How to get into Mixed Martial Arts?

I'm looking into how to get into boxing first then other stuff. Also I'm 13 is it to late or do I still have time. I'm 6'1" 1/2 and around 212 pounds so I definitely have a good start but I'm sort of chubby. Whats a good exercise routine. Also I play baseball a lot do you think that would get in the way if so I wouldn't want to start mma.