First of all I have opened the Gmail app and I have logged in, then I followed the following steps:

I’ve entered the «Settings» snail that sits on top.

Then I went into «Show all the settings»

He searched the tag section alongside «General»

I went down until I reached the section that says «Create a label», which will let me create them.

I have made a label for every teacher I have and another for my classmates.