Always good to have a 3rd physical backup as the cloud can go wrong.
To do what you want is all over the web.
I have an HP Chromebook Model:14B-CA0013DX Never have had an issue. I have all my important papers downloaded as pdf"s and they are in my dropbox as well as google drive. I wonder is it necessary to get either a USB flash drive or micro USB and also put my things there. I don't want to lose access to the things I downloaded like music. pictures and other things. Is google drive/ dropbox enough? I also want to password protect the USB or micro sd card so no one can access my files is that possible??