If you're using the new beta Members features in Ghost, you'll need to start by connecting your Ghost install to your Stripe account.
In the Labs settings area of Ghost Admin, you'll find all the settings needed in order to enable paid memberships and subscriptions on your site.
After enabling the feature and selecting
Paid as the site-type, enter your Stripe API keys to finish connecting your Ghost site to your Stripe account.
Once you've set Monthly and Yearly prices and clicked
Save, Ghost will automatically create Stripe plans for your users to subscribe to. You can now start using paid memberships and subscriptions on your site!
Your site is connected directly to Stripe, and Ghost does not take a commission.