Do i get a Apple Pay card in the mail

"Apple Pay" uses a variety of cards including Apple Card, Apple Cash, and any of your current credit or debit cards that you add to it.

If you meant "Apple Card" -- you only get a physical Apple Card by requesting one (after you have been approved for the Apple Card). Request and activate a titanium Apple Card - Apple Support If you haven't applied and been approved for Apple Card, you need to do that before requesting a physical card. See: Request and activate a titanium Apple Card - Apple Support

Or if you meant "Apple Cash" -- there is no physical Apple Cash card.