Got approved for my first credit card (Discover It Student Cash Back)

I'm an international student, and I got my social security card today and applied for a student credit card with Discover and Capital One, and got approved for the Discover It Student Cash Back with a $500 limit and 25.49% APR and was denied pre-approval for Capital One Student Savor (although Capital One owns Discover). I enrolled in Autopay and linked my PNC checking account to Discover. What should I do next?