Panasonis TZ18

Two questions here.(Note, layman!!)

I want to take low light indoor pictures in a classroom of about 50 people, can you tell me the best settings.

I don't know how to get a timer running when I do a movie. It appears from the manual, it should happen automatically and all other cameras I have used have had the video duration running. Do I need to do something in settings or could this be a fault?

Many thanks in advance.
For the group shot open as many window drapes as possible and turn on as many lights as possible to get as much light into the room as possible. Use a high ISO like 1600 if needed. Shoot an 18% gray card for proper white balance immediately before you do the group shot.