Overlaying Multiple Clips

I will preface this by saying that I'm an absolute novice when it comes to Premiere Pro. I'm trying to make a video where two clips are always playing, one on top of the other at the same time, but they alternate which clip is more prominent while the other is still slightly visible in the background. If there is a name for this type of editing or transition that would help and if you could also give me some tips on getting this effect I would greatly appreciate it! If not I'll at least be able to youtube the correct transition name. My guess is it has something to do with layering the clips and changing the opacity but I am unsure?

I have a clip of me driving to Vegas. My "vision" is that I want to always have the clip of me driving to be playing while clips of Vegas are fading in and out, almost like a foreshadowing effect of where my final destination is.

I hope that makes sense and is a very simple thing to do. I appreciate the advice and if anything is unclear let me know!

Cheers!