I have the USAA banking app and can see where purchases are made and how much. I was wondering if I got a visa gift card and bought something with it, would it show up in my history in my bank account?
No. The purchase of the Visa Gift Card would show up (if you bought it using your USAA card), but any subsequent purchases using the Visa Gift Card would not be handled by or show up on USAA.
It is not truly anonymous - if you were to buy something illegal with the Visa Gift Card, then it is possible for the purchase of the Visa Gift Card to be tied to your use of the USAA card to buy it, and therefore to you - but if you're just concerned with normal privacy, the Gift Card does remove your purchases from your normal accounting details.