Newbie question

I am confused about video sources, number of devices, etc and appreciate any help in choosing a package. I teach art lessons online. I am not looking to get fancy, just something so that I don’t have to monpve my phone back and forth during a lesson. I would like to use my iPhone, iPad, Macbook (not sure which I will find best at this time) with picture-in-picture (one on me, one on the easel). I would also like to have my co-worker use her phone (Also iPhone) for in session demos on occasion. Does my phone and hers count as two devices or my MacBook and phone? Basically, I am just confused! Thank you in advance.

Hey @Cre8

Please see