As a reservist, your OJT will be comprised of the work you do on your UTA weekends, annual tours, and deployments.
There is some kind of program where airmen out of tech school get put on 90 day orders at their home base (optional) to complete a lot of their OJT. If anyone knows more about this option please feel free to chime in. It wasn't offered when I came through--I only know from a few new people in the unit who chose to do this. I don't know if it's new or even if it's AF-wide.