Can I extend my Mac desktop?, yes, you can run two screens and have separate images on each. Ideally, you could have a presentation or Video running on the Projector /TV and be checking their work on Google Classroom or entering data into Compass on your MacBook.
I have created a short video that explains the process. If you need any help, just let me know. Best to practice a few times on your own in a seminar room or another empty space with a projector or TV.