Second the Buffalo's comment. Dirty ammo that, in the few rifles I used, also is not very consistent. Not worth buying at all.
For cheap ammo, I would recommend you go with Walmart/ Federal.
Craigslist is also an option, and you may have the option of shooting it before buying. If you're looking in the lower (< $ 400 ) range, new will get you a warranty, and the bow will have new strings.
If you're planning on going to the Great American Outdoor Show, you can shoot several...
Another option... National Safety Council did offer a 2- hour specialty course dealing with just tournequet use. In Md, I think it's Chesapeake Safety Council. Dan Kellum at CSC could tell you more about it.
Start with a 22, or even a pellet gun.
Meet them at the house and show them the safety rules, how the gun operates, loading / unloading, then practice with a spent casing at the worktable. Repeat that with PPE on for rehearsal.
Go to the range and shoot, demonstrating first. Give them...