How does order fulfillment work after a sale on Shopify?

I made my 1st sale on the Shopify store and I don’t understand how to collect payment.

The customer purchased 5 items.

When first going to fulfill the order i was promoted to enter my paypal which i did (was curious if there’s any other form of direct deposit I could use)

Next, Shopify told me to wait until the payment was processed. Shopify asked for my credit card (Which i thought was odd) I entered it and it seamed like i was prompted to “buy” my customers order.

Did i pay for their order, was i scammed, or is the payment still going through?

This is where i’m at, can someone help me?