How do I find a list of my auto payments and how much each is?

You can go to your subscriptions overview, to see your current subscriptions that have billing through Apple.

See your subscriptions overview - Apple

You can go to your purchase history, to see any past billing through your Apple ID, including subscription fees.

View your purchase history for the App Store and other Apple media services - Apple Support

What are auto payments? Are these subscriptions for Apple services and apps from the App Store or what exactly?