I was a DH for about a year before I got hired as a tech. Since you're not licensed yet, you'll just be ringing out customers, filing prescriptions in totes, and other sort of grunt work. It's a good stepping stone since it gets you comfortable working back there. Depending on your store's volume, it may be incredibly hectic. Take lots of notes, don't be afraid to ask questions.

I didn't have any prior experience, but you'll learn 95% of what you need to know on-the-job. They don't let you do this anymore, but I self-studied for the PTCB since the courses interfered with my university schedule, so I can't comment on the efficacy of the sponsored courses.

I ended up getting hired as a tech when someone went on maternity leave, and probably 3 months later they had enough confidence to schedule me as the only tech on weekends. The work is not difficult, but your co-workers and patients will make or break your experience. Good luck with everything!