I would suggest speaking with your bank and asking for the origin of these charges as Shopify is unable to charge you unless you sign up for an account and provide your credit card details. The multiple payment attempts in such a small space of time is also irregular and Shopify does not attempt to collect payments at this cadence.
Exact same thing happened to me, and I caught it after 5 transactions thanks to notifications of N26 while it is happening. I blocked card immediately. Each transaction was 13.83 euros and they attempted multiple times. 5 more times that I didn’t have sufficient amount for. There’s a fraud dispute going on but seeing name Shopify, together with Shopify logo in the bank app was strange. Official name of the merchant from each transaction: