Separate music library on iMac

I want to use my iMac to organize my extensive DJ music library. I have multiple apple devices - MacBook Pro, iPhone, 2 iPads, Apple TV and iMac. I also have over 20 flash drives filled with folders of music. My music has appeared in different folders in many different locations. Some folders have the part of the same name but different date and different songs inside. There are duplicate songs and inconsistent syncing to the cloud. I also have 2 old MacBooks pros with music content that are not on my network at this time.

I want to dedicate my iMac for music only. I have over a terabyte of music. I don't want to sync anything to my iMac because I don't want to create more duplicates or get confused about what song is coming from which folder or which song is synced or not synced. I also don't want to run out of space I want to use my iMac to gather, organize, edit and store one super music library of all my songs. I don't want to use Apple Music because that will create another syncing nightmare. How can I set my iMac up for this project within the above stated parameters?

My iMac is a 2019 27inch 6-Core intel core i5 running Sonoma 14.6.1