Restore iTunes library

A couple weeks ago I had an issue with my Mid 2014 iMac (running macOS Catalina). It wouldn't start up past the black loading bar at restart even after reinstalling the software or doing disc recovery/first aid so I enlisted my friend to do data recovery and restore the iMac. 

He was able to successfully recover my data (and not my applications) onto my SSD. Unfortunately, this means that my iTunes library is on my SSD but isn't it iTunes. I found a couple iTunes libraries from past computer transfers. In iTunes, many songs were repeated and it wasn't my most updated library that I developed on my iMac (But a library from my old PC laptop). When I tried to delete the duplicate songs it found in the itunes library, it seemed to also delete the originals along with the copies. Id like to start over again to not mess up itunes library any further and start from clean slate of 0 songs on iTunes.

I am looking to do a couple things...

1. Determine the most updated iTunes library from my iMac out of all the itunes libraries on the SSD. First before doing that though, I would like to know how to easily insert a library/delete it from iTunes so I could figure out which one is correct.

2. How to delete the iTunes library inside iTunes but not from the computer itself so I can try out different libraries to see which one is correct

3. Is there an easier way to restore a playlist or library that I already have on my phone to the computer? Like a reverse sync? Or maybe a way to restore through iCloud?

Thank you for all your help and time!