I think what Cassie is referring to is stop encouraging the head butting. If a goat is head butting you, it might seem like play, but that can be dangerous. I suspect you probably think its cute and "headbutt" back with your fist. Stop doing that. Then, if he tries to headbutt you again, give...
Please don't get a buck if you intend to keep it for enjoyment. The only reason people keep bucks is for breeding. It seems to me like you are getting this goat for the purpose of enjoyment, like as a pet. Bucks make terrible pets, they smell bad, they are hard on fences, and can be dangerous...