Hi, and welcome to the community
Go to your Galaxy store app and tap the menu icon and tap subscriptions. Anything there? Also look at 'Receipts'
Did you sign up for a free offer that's now ended? If you have a Samsung TV, maybe something on that you've subscribed to.
Did you recently add any of your payment cards to Samsung pay? If so, they could be authorisation charges that should get refunded automatically after a few days.
Check with your bank and ask them to investigate.