Demotivated

I recently got into warhammer with some friends because of all the media and was excited to finish painting my army to play, but one of the friends decided to play castodies cause he wanted to be the best thing in the verse. I've looked up some info about how to fight it but everyone seems so down when it comes to facing them. I just wanted to play some fun casual games but not I feel like ittl just be competitive and unfun. Any suggestions or thoughts