Ahh, okay. I've done everything I can to avoid sports as much as possible in life, so I don't really know how people who enjoy sports act.
Being a sports fan is absolutely no different than being any other type of fan. You watch something that entertains you, you want "your team" to do well. You're happy when it does, you're despondent when it does not. You talk about it with others. There are people who hate what you love, and vice-versa.
Dead-nuts on just like being a genre or franchise fan.