connecting MacBook to projector and keeping MacBook as the ‘main’ monitor

Hi I have a MacBook and am starting to sometimes connect it to a projector (via hdmi or airplay with an apple tv) to use it as a second, separate display (not mirrored). It works well except that every time that i connect the projector via hdmi or airplay, it always moves all my windows from the MacBook to the monitor or projector and also moves all my basic system functionality (like my dock, volume indicators, login screen, new windows that i open, etc) to the projector.

I want to make it so that basically everything stays on my MacBook screen, including most of the windows and all of the basic system functionality. The only thing that i want to use on the projector is one or two browser windows in chrome or firefox so that i can watch videos on the projector while working on the MacBook.

How can i make it work like this?

Thanks,
Dan

With both display connected, go into System Preferences > Displays, and select Arrangement. Move the whit bar at the top, to whichever display you want to be the main display.

https://support.apple.com/en-us/HT202351