Mary Cooch

Eric Eric - I know what blocks are and yes they are available for version 3.11. See this video made especially for 3.11
Also see the 3.11 documentation on Blocks

Which block??

Hello Maria
Well the first thing to say is that only BigBlueButton comes as standard in Moodle - the others are extra plugins.
The answer to your questions 1, 2, 3 and 4 is Yes - BUT - although BBB is opensource, just as with Moodle, unless you are technically able to install your own server and run BBB for free, then you would have to pay for more functionality than the basic free version. In the documentation I linked to before BigBlueButton it outlines what is available in the free tier hosting. If you need more than that then, you are correct, you either have to pay https://blindsidenetworks.com/services/ or install it yourself.
I don't have experience of the other systems within Moodle. I imagine they are more expensive though.

Hello Terry. I can do this if you can tell me the URL of your site - either publicly or if you prefer via a private message. Please note that the documentation Site registration provides a link to the contact form you can use if you need to give more details or if the issue happens again and you don't want to use this forum.

Visvanat: to be able to see that content you need to have a legitimate account on Moodle.Academy, as indeed Eric does.