Hi
Note that the prompt mentioned in Toadstool's post...."Drag and drop your video,text and image clips here to overlay" will only appear when you have already placed a clip or image on Video Track 1. Until you have done this, Video track 2 remains hidden.
Dragging and dropping another clip or image (it can even be the same clip or image) onto this narrow band where the prompt appears will create the labelled Video Track 2 with its thumbnails, and an Audio Track 2 below Audio track 1.
Clicking the + on Video Track 2 at the extreme left of the screen will expand the track so you can see the thumbnails more clearly.
Note also that anything placed onto Video track 2 will obscure what you have below it on Video Track 1....hence it's description as an "Overlay " track. The audio tracks in contrast will mix.
The same action will produce Video Track 3...4... etc.
Nat