Okay, slowly but surely I think I'm getting it. I peddled around the neighborhood and practiced shifting. I ended up with the front on the smaller gear and the back on the 4th largest gear. That seemed easy and comfortable.

I do have to stop now and then to cross an intersection, so at the point for "downshifting" what is the best way to do that? Do I switch to the larger front gear, or leave the front alone and shift to a smaller back gear? (I think the front is easier)

I really appreciate all the responses. I feel like such a dummy because I don't know how to ride a 12 speed bike. I am not a confident cyclist so I ride only on safe, easy routes but hopefully I'll get better skills after mastering this bike. Thanks!