Unity multiplayer

Hello, I'm Actively working on my university senior project. I planned to make a 3D online virtual classroom ising unity.

I have sone questions regarding unity multiplayer.

1- Do I have to use 2 or more headsets to test and run the game? ( I have only one)

2- Does quest 1 will support all the functions and packages supported by quest 2? ( I have quest 1)

3- what advices would you like to give me.