> I haven’t used the card for much yet but would like to build credit.

Only requirement to build credit is to pay obligations on time. You don't have to carry a balance to build.

> I’d also like to pay things off in a fair amount of time

21 days is a fair amount of time.

> so I can cover both smaller expenses but also larger expenses by freeing up credit easily

You have savings. Use it. It's very expensive to borrow with a credit card past the due date.