Best Way To Backup My Computer

Recently my friends computer crashed and he lost all of his data that he had on his computer. Most of the things which were stored on the computer were important and it also included photos and videos as well as documents. His computer was working fine and all of a sudden crashed, so just to be on the safe side I would like to make a backup of my computer, so just in case something does happen I know that I have a backup of my data.

Please suggest what ways I can make a backup of my computer.
Create a restore point on the computer and also save any important files or folders on an external hard drive or cloud storage.