Any charges on your account must be initiated by you in some way even if you are not aware of it. Apple will never just charge you out of the blue. You must have done something to cause these charges to happen.
Verify your account for active subscriptions and pending charges.
If you are the Organizer of a Family sharing group, purchases and subscriptions started by other members of the family group will be charged to you.
You would need to look in there accounts for those charges.
click here ➜ If you see 'apple.com/bill' on your billing statement - Apple Support
and here ➜ View your purchase history for the App Store, iTunes Store, and other Apple media services - Apple Support