Gumroad lets you create simple payment pages to sell pretty much anything online - but it’s especially built for nontechnical people. I’m a fan of Gumroad - I think their pricing is a little unfair, but for early-stage prototyping, they’re a beautiful tool. There are plenty of other payment tools you can move to later on, like Stripe, but if you’re building a little test store, I personally always use Gumroad.