As a member of the LCHSRailers domain, you can have a free basic account that does not kick you off after 40 minutes, so make sure to sign up.
Using a virtual background may help you/your students feel more comfortable about their living environments and be more apt to be on screen.
Check out all the different ways you can share your screen while still see all your students in Zoom.
Breakout rooms are a great way to create some small group discussion. You can pop in and out of each room. There is a chat enabled in each room also, but it is not saved/shared with the whole group once breakout rooms are concluded fyi.