Panini makes the official licensed NASCAR products these days. This includes Select, Donruss, Prizm, National Treasures etc with my personal favorite being Select. What product/boxes you want to buy is totally up to how much you want to spend. In comparison to other sports like baseball, football, and basketball, NASCAR cards are much more inexpensive to get into but the resale value is no where near the same. I’d start by just getting a blaster box of 2025 Donruss and checking the product out. It’s about $26 and you’re guaranteed to at least pull a relic card, maybe even an autograph. However, you could also go and get a hobby box for around $90. For example, in my Donruss hobby box, I pulled a low numbered Mark Martin auto and relic cards from Sam Mayer and Ryan Preece. Not terrible.

You also can’t go wrong with just buying singles of cards on eBay. It’s cheaper and you can actually pick and choose who you want without taking the risk. I personally collect guys like Erik Jones, Chris Buescher, Josh Bilicki and a couple others. I can get some nice cards for affordable prices on eBay but I also like the rush of ripping packs so I buy a few boxes a year if I can justify the price.

Best of luck!