How do I use the card? Is this a regular credit card ?

Do you mean the Apple Card? Or Apple Cash? or a Gift Card?

The Apple Card can be used like a regular MasterCard based credit card yes. In places that take Apple Pay you can use your iPhone or Apple Watch to pay for things. In places where Apple Pay is not accepted but Mastercard is you can use the physical card. You can order a physical Titanium card if you want something you can hold.

link->How to make purchases with Apple Card - Apple Support

link-> Request and activate a titanium Apple Card - Apple Support