OP, good luck, but as others have said in different words, be careful. Power definitely tends to corrupt. It can get away from you very quickly. But one can also screw up with any car. My first car was one I bought at age 21, but before that I was being a stereotypical teenager in a parents-owned 1959 straight-six automatic Ford station wagon. Definitely not a chick magnet, but you can still kill yourself regardless. I hope you do fine. Probably wouldn't hurt to join BMWCCA and take some of the courses they offer.
Mods-Etc: Quaife LSD w/VAC finned diff cover, M3 Rear SF Bushings, M3 sways & OEM Susp Front/Rear Cmpnt Kits ('cept strut brace), GC Caster/Camber Plates, AC Schnitzer M3 Sport Springs, JRZ RS1 dampers, JBD 100%, Goodrich SS brake lines, non-stggrd APEX ARC-8 18" wheels with Michelin PSS tires (winter OEM 17" wheels and Blizzak LM-25).