Imagine you really like going to a special club with your friends. You have lots of fun there, and you really like the people you meet. But there are some rules in the club that you don't really agree with or follow, like you're supposed to dress a certain way or act a certain way. You still go to the club and have fun with your friends, but you don't really follow all the rules like some of the other kids do.
Being a cultural Mormon is kind of like that. It means that you like being part of the group of people who follow the Mormon religion and beliefs, but you don't necessarily follow all the rules that come with it. You might still go to church or hang out with other Mormons, but you might not believe everything that's taught, or you might do things that are considered against the rules. It's kind of like being part of the group and enjoying the culture and traditions, but not necessarily believing everything the religion says you should.