Restore old website to new ISP

I have a set of files relating to a commercial website that used to run perfectly well. I now want this website to be made to run as a test site, sharing ISP with an existing working site (the ISP has informed me that this is possible). The existing website should not be affected, and files should be segregated. I would also value input on which files are redundant (there are a few iterations - I only want the latest version to run), and possible archiving of unnecessary files. The coder will need to be able to access dropbox in order to see and use the set of files. I will then expect the coder to move the files to the website area