Welcome to the flintlock family! You're probably going to need flints, a pan primer and a vent pick (optionally you could a flint knapping hammer but it's not required). First of all, you're going to want to get the proper size flint. A 5/8" flint is likely going to be your best fit due to the lock being similar to a CVA lock. When you position the flint in the lock, make sure that you place the flint in a piece of leather and also ensure that when you pull the trigger the flint doesn't scrape the barrel and the flint is square with the frizzen. Next, you're going to need a pan primer. A pan primer is just a device that dispenses powder in the pan easier. There's a bunch of styles of pan primer, but for most needs a brass pan primer should work fine. Occasionally, the touch hole will get blocked by fouling or something, and you need to pick it out so the main charge ignites. You can just use a common needle or fine piece of metal that fits in the touch hole as a vent pick (that's what I use personally). A vent pick is also good to have around in case you need to siphon some powder down the touch hole because you dryballed.
Now when it comes to shooting, Mr. Beliveau (duelist1954) on YouTube makes some great videos. Have fun with your new gun!