I am no expert, but have and picked a few. The tool is really great, I think. You just have to treat it as a precision tool.
On the locks, it helps to check the keys. If it is a butterfly disc key, it's probably a better lock. You can count the discs approximately also from the key and see how the discs are spaced. It tells you a lot about the quality and a bit about pick resistance.
I have some of the chinese cheap locks, which are fun but easy. They tension from the rear, but the dd pick makes short work of that anyway. Doesn't cost much and it's fun.
I have some of Lidl (Parkside branded, I think), which is a supermaket chain that sells different hardware every week. They were as cheap but have false gates and more discs. Much more fun to pick but careful not to break the pick when in a false gate.
I have an axa bicycle lock that has spinners with gates and plenty false gates in the normal discs. Fun to pick but certainly more difficult.
I have two much higher quality locks in the naughty bucket because of many spinners, tensioning from a random disc and discs very deep in the lock. One of those I think I can open with my home made front tensioner pick or with the sparrows pick if I modify the tensioner, or make a new tensioner.
Don't be too afraid of a lock you can't open. The harder locks actually give so much better feedback that you learn quicker.
I'm not in the USA, but you can also check people like Albert Lebel on youtube. He has a lot of dd videos and recommendations on locks and he is based in the usa.
https://m.youtube.com/channel/UCSkq1SxMwDFYD6nQaVHF6-Q