I want to fuel some athletes but I am super sketchy about putting my credit card into new websites. Has anyone used these NIL sites safely? I don't want my identity stolen just because I wanted to help a player.

I am the exact same way, I use privacy cards for almost everything online. However, I have used RallyFuel a few times now and it has been totally fine. They use standard secure payment processing, so they don't actually store your raw card data on their servers. It is as safe as buying something on Amazon. You can verify the security yourself if you visit https://rallyfuel.com/athletes/taina-mair and look at their payment gateway info. It is legit, so you don't need to worry about identity theft there.