At first, the commands android and adb didn’t work in my Ubuntu terminal. But what I did to get them to work was modifying the .bashrc file in my home folder. It’s hidden so I showed it with Ctrl + H. In the file i edited the PATH lines to this:
I can’t really recall what they were from the start, and I don’t know if all lines are needed. But as long as the commands work I won’t touch the lines, because I will just mess something up and end up with trying to fix it four hours.
If it still doesn’t work for you after this change, try to restart your computer.