Or how do I switch to Nav2? Nav1 is right there in the center but I'll be darned if I can find where to switch it to Nav2. This is the Just Flight free 757 btw.

The radio in the centre is for tuning in the ILS frequency which is linked to NAV1. The NAV2 radio is in the bottom left corner of that panel. It can also be tuned using the RAD NAV page of the CDU.

 

Thanks

Martyn - Just Flight