In reply to SebioJazz.

Hae you tried some of the resources on the Getting Started page?
For cues, you can add an instrument to the project in Setup mode, but then click on the full score on the RHS and untick the new player. They then don't exist in the score, but are still in the project so you can cue from them.
Alternatively you can do it manually by copying and pasting notes into a new voice (so that you still have bar rests for the player who isn't playing), change the size of the new notes to 'cue' in the Properties panel and add some text with the Shift-X text tool for the label. Often adding a player with the right notes is quicker/easier.