Rock Finding UV Flashlights
This is the flashlight I would reccomend the most on Amazon. Its a bit pricier than some other options, but notice that it offers a good spectrum range compared to the others, which usually only offer one wavelength.
This next one isn't as diverse as the first, but it is VERY bright. This will allow you to spot rocks at a greater range, although you'll miss some that may only be visiable in a different spectrum.
If you're just getting into the hobby and aren't sure if you want to invest in a nice light, then this is a great starter or gift flashlight. However, because it is the cheapest and most popular on amazon, the likelihood of you finding anything on popular beaches is low, since a lot of hunters will at least have this light. Still a good light though.
This last light is a low power, single spectrum, portable option. I wouldn't suggest it unless portable is what you're looking for. It will work, but it won't be great. This is a handy option if you already have some rocks that react and you just want to show them off to others. It is USB C rechargable.
Safety Glasses #1
These are a bit pricey, but they're some nice glasses. They are meant to stop you from getting your eyes burned out by lasers, so they certainly should do the trick when it comes to flashlights.
Notice they specifically say they protect from 190-490nm. All the flashlights I have linked fall into that range.
You'll save a couple of bucks on these glasses compared to the nicer ones, and they should be enough to prevent any damage. I'd trust them for myself, but not my kids.
It says UV 400, but I'm not exactly sure what that means since glasses should cover a range. Their ad does specifically say that it's perfect for UV flashlights.
I'm really only posting this one so that you have a cheaper option if you really want it.