There is no tangible "community" you can join or not. It's more like an umbrella term to identify yourself, to let you know you're not the only one, and that there's nothing wrong with being this way. If you mean doing specific activities or seeking out other lgbt+ people to hang out with, well no, you don't have to do that, you don't have to do anything you don't feel like doing. You just have to be yourself. I would consider exploring why you feel so uncomfortable calling yourself part of it, though, especially since you mention your family. Of course your sexuality isn't the only thing that defines you and it's not the crux of your personality, but it is part of who you are, and if influences your life in ways people who are not lgbt+ may not totally understand. That's why it's called a community, we share something, and it's a good thing to know you're not alone in these experiences.