Changing the immediate is stressful, especially when teen have a hard time connecting with peers. Fortunately, the school year will start soon and they will be able to be with other kids their age, assuming that they are not home schooled.
In the mean time, talk with your kids about what they like, what their interests are. Perhaps they would like to sign up for a youth class at the local community center. Your kids might be able to find friends with similar interests there.
are your children shy? if they're like me, it takes awhile to bring friends home. they might have friends at school, that they don't feel comfortable bringing home. I am about to start my second year at school and have only brought one friend home to meet my parents. I just didn't feel comfortable bringing people home yet. Give your children time, and they will bring friends home.