What is the interest rate on my card?

See the following from Manage your Apple Card account - Apple Support

(the APR is the interest rate)

Check your credit details and limit

1. Open the Wallet app on your iPhone and tap Apple Card.
2. Tap the more button .
3. Scroll to Credit Details.

You can see your account Credit Limit, Available Credit, and APR.

Goldman Sachs will need your credit history with Apple Card to inform

any request for credit limit increases on Apple Card. This can take six months or more.