On the US forums they have a post about finding old friends from 2004-2006 era.
Can we get this aswell?? heres the orignal post from US forums
It is on the EU forums it’s just that no one can post in it. Maybe checking the Classic forum would have helped you.
https://eu.forums.blizzard.com/en/wow/c/wow-classic/classic-connections-2004-2006-find-people-here
Heya,
Just to add to Dottie’s link: You can post in the open threads in that forum. Just find your old realm/faction and you can post your details there. 
Have a few seconds to spare? Let me know how I’m doing!
You can click on the links in the first post to navigate to your old realm, silly me thinking you just posted there.