There isn't a single path to the goal. You actually sound like you're already doing a lot of what many DBAs do for their entire career, set up servers, set up backups, handle security. Certainly there is a lot more to it, but that may be all that's needed to do a minimal job.

I recently answered a similar question over at ASK SQL Server Central. I'll just link to that rather than retype it. I like Magnus' answer too.