I bought two tickets with mine and my friends name on it can I still use my friends ticket for another friend since he canceled last minute or is it not possible since his name is on it already ?

You're good to go

Nobody checks names on tickets

Yes of course. I had the same concern once but we got up there and it was fine.

If your friend hasn't used the ticket then your another friend should be fine to enter the park since they make u scan your index finger when u enter.