There must be hundred different tutorial on this topic and the above is a mouthful but with a bucketful of applications for a less than $500 setup you can create rapid prototypes of user demand.
Instapage is a terrific web creation site with great templates for landing pages and even whole commerce systems. It is a great way to have a test destination for your offerings. It’s expensive at $150 a month but it can save millions by letting you test offerings.
Facebook is the key vehicle for testing. You create some Facebook Ads and then connect them to the Instapage site and soon you will start getting all kinds of metrics for user interest.
Then use Google Analytics to figure out how the order process goes and monitor how instapage works.
Namecheap is the way to find great test domains to check responses.
How to create ads
The easiest way is to be a Canva subscription, it has templates for Facebook and other ads. Then you can use the embedded images editor or use Unsplash to find good images.
Images are really the key to great ads.