Hi
The overlay track is not immediately evident until you place a clip on the main sequence line (Video track 1) when it becomes labelled with a prompt.. Drag and drop your video, text and image clips here to overlay. It is situated just above the main sequence line and is labelled Videotrack 2....Videotrack 3 ...
Videotrack 4.......etc. if and when you add any clips to them.
You can have many of these extra tracks. Each one is an overlay track and plays preferentially over anything placed on the lower tracks. The soundtracks for these extend below the main sequence soundtrack (Audio Track 1) and are labelled in a similar way. However these tracks mix together and don't overwrite unless you choose to mute a selection.
Nat