I am trying to add a new website 9am.design into a hosting account that previously has 9am.agency hosted on it. Now, when I am trying to install a new WordPress site, it warns me that it will overwrite the files. Does this delete my files in the previous WordPress site (9am.agency)? I don’t want to lose any of my previous site’s files.


Yes, It will replace the old with new setup. Try to install on subdomain or add-on domain. Or take backup of current setup and download it.
9am.design is a new addon domain. I need both sites running and old files should not be deleted. How can I do that? Please help. It’s urgent.