I recently lost my friend Kenneth Ghostmender (he's fire school). I know you can't really recover lost friends so if anyone knows him, please tell me.
Oh no, that's very sad
I suggest you make a new thread with his name as the subject so that if he looks at it or anyone knows him they'll see it straight away. I'm not sure what section to put it in - Ravenwood Commons is maybe the right one. It gets a lot more attention there than the world ones like this Celestia section.
In the main post let him know your wizard name so he knows it's you and maybe say where you met or what you were doing last time you were hanging out - eg we met in Krok last year and were questing in Celestia.
He's fire, but also indicate what kind of level he'd be - if someone knows a wizard with the same name they'll be able to check more easily and help you reconnect
Hopefully he will see your post or someone who knows him will and you'll be able to reconnect
In game, you could also check with anyone who you may have both met together in case they added him too.