I am very new to VV and new to video editing, but how do you overlay a video over a video track, for instance, when a video is playing how do you get a video to play at the same time but transparent over the other video?
If you have two tracks of video in Vegas you will see the uppermost track. if you wish to see the lower track thru the upper, you have a slider on the track header to the left. Drag this slider left to change the opacity of the upper track & the lower track will start to show thru.
Or picture-in-picture, or create a mask, or alpha channel, or parent/chld composite, or. . . . -- it all depends on the effect you want to create. There are a TON of tutorials and samples out there, maybe start looking here: