I got a cheap set off of amazon at the time, which worked fine, and it looks like someone has already provided a link to a more reputable business. Most sets will have the same core of tools in them, which will be the most useful, plus maybe some obscure shapes in there that serve a niche purpose.

If you’re interested in getting into the hobby, there’s a discord server called Lock Pickers United that ranks basically every lock in existence on difficulty, and will hand out “belts” a la martial arts, when you can show proof that you’ve picked a lock from different tiers. I never got very far but it seemed fun.