Thank you everybody for your advice!
I was very surprised at your willingness to help.

I guess I have to go through PDF manual. I put it on Kindle for easier reading.
And when I have time, I will go through videos.

As for starting a new line after inserting an odd bar (2/4), I was able to delete the 3 following bars. Checking on "Chordsheet and Notation - Start a new line" from Bar Setting did not do what I wanted. (I don't know what it does...)

Inserting a bar also worked.
Regards,