Diva Canto has created a number of YouTube videos (originally in live session on twitch) to document the steps to create an OpenSim grid (version 0.9.1.1) on Linux Ubuntu…
https://youtube.com/user/divacanto
OpenSimulator: How to set up a multi-simulator grid (Part 1) [2hr. 20 mins.]
OpenSimulator: How to set up a multi-simulator grid (Part 2) [1hr. 2 mins.]
OpenSimulator: How to set up Wifi on a grid [57 mins]
More details and advice for educators using OpenSim in classes can be found in this New World Notes blog post (11-Feb-2021).