Zoom In / Out
To zoom in / out on the timeline, use the slider on the top-right corner of your timeline.
To add a track, click on the + sign at the beginning of each timeline track, this will allow you to visually separate your different elements.
To delete a track, right click on the track you want to delete and choose Delete track.
To change the order of your tracks, right click and choose Move up or Move down. The media on the higher track will be shown on the front layer of your player.
Move from one Sequence to Another
When several sequences are opened in the editor, they always remain accessible via their corresponding tab. You can use them to navigate from one sequence to another.