Providing a community space on line, creating co-hosts and enabling all participants to screenshare

[Amolandi]

I have set up a recurring meeting for a community of mine to meet regularly weekly
I have set it so the participants can join whether or not the host has started the meeting
The system will not let me set up co hosts in the set up - why not?
I also can't seem to be able to allow screen sharing for all participants except when I join the meeting as well
I don't join every meeting - I have co-hosts which as I said - I can't set up ...

What can I do - I can't make myself available every week ...