I am in 6th grade and I do not feel popular I know that popularity is not important but I want to be popular can you help

Hi - please keep your questions together so that we know more about you as a whole.
I'll try to give advice about this, and also about the boys who have crushes on you.

Being popular is defined by what 'a lot of people' think is true, but it really doesn't mean much in other, less noticeable groups. Every school has it's groups of close friends and some are just quieter about it than others. If you have close friends, you are popular in your world. Popularity changes too. In 6th grade, you are really just starting to be someone apart from family, and it's a struggle for most of us, all the way through high school. So.. do you have a bestie or two?
As for crushes, turn them down in a nice way. Crushes are tough on the one having it. Just say 'I don't want a boyfriend, sorry, you are a nice guy who will find someone.' Or 'I don't want to go on a date' or whatever applies to the situation. Continue to be friendly so that the poor guy isn't more crushed than he already is (I guess that's why they are called crushes). If he doesn't give up, then you have to ignore him for his own sake.