Can e recover my character from before?

I had a Rogue ELeganso level 80 before on this server. is is possible to recover it?

If you delete a character yourself, it's possible to recover it within 30 days through Warmane's website account services. Outside of that, no.

If you don't have a premium account, and haven't played the character in a while, it was likely lost to the yearly Inactivity Cleanup and Gold Squish, which removes characters that haven't been logged in all year. Either way, you'll have to make a new character, unfortunately.

One friend told me he also had character before and he recovered it from a ticket and giving some info about the character.

It's possible your friend lost access to their account, either by forgetting the account credentials or having their account stolen, and were helped with account recovery. However, I don't believe there's any way to recover lost characters, especially those deleted through the character menu (after 30 days), and any lost to the annual inactivity cleanup.