Moving iTunes library
How do I transfer my iTunes library from an older iMac using a copied Media folder and portable USB flash drive?
iMac, OS X 10.11
How do I transfer my iTunes library from an older iMac using a copied Media folder and portable USB flash drive?
iMac, OS X 10.11
You can transfer your iTunes library by copying the entire iTunes folder containing the Media folder to your portable USB flash drive, then paste it into the iTunes folder on your new iMac. Make sure to authorize the new computer if you have purchased any content.
See the following:
click here ➜ Make a split library portable - Apple Community
and here ➜ Move your iTunes library to another computer - Apple Support
Moving iTunes library