How do set up a form that links to a Stripe subscription>

Customer journey: 

lands on home page of my website (not a wordpress site)

reads about a subscription

decides to select one of the two subscription options

clicks "register now" or "buy now" or similar

button takes them to stripe to complete their bank card details. 

You can integrate your form with Stripe and set it to Sell Subscriptions.

The Subscriptions can be created in the form builder or you can fetch them from Stripe.

This way, the users will fill out the form and pay for the subscription from the same page.

Help Articles:

How-to-Integrate-Stripe-with-your-Form

How-to-Setup-a-Recurring-Payment-Option