I’m trying to update the ghost to the latest version but it is giving me an error saying that the version 12 which is the latest version is not supported, any suggestions?
Howdy there 
. You can find more info on supported versions of Node for Ghost on this FAQ page:
Hello there
Is there any way to override that? I really don’t want to downgrade my version…
Have you looked into using nvm? It’s a very useful tool for managing versions of node:
Ghost has been made to work with the LTS (Long-Term Support) version of node. To quote the page linked above:
By following LTS we can focus our efforts on meaningful work and keep our time spent on node versioning to a minimum. It also allows us to delay the support impact until later and give us a chance to grow our team to cope with the support in the meantime.
If you want to run Ghost on the latest version of node you can, however we are unable to offer support for any issues.
Hope this clears things up 
Hello there
I installed that, now what should I do?!
Hey, did you move onto the usage section fo the documention? Should show you how to use the package and switch between versions GitHub - nvm-sh/nvm: Node Version Manager - POSIX-compliant bash script to manage multiple active node.js versions