i had this problem, too. the first thing i did, was starting conversations with family and friends out of the blue. but i would not stress over it. if they responded, cool. if they didnt, cool. i needed to learn that their world does not revolve around me, but my world does revolve our myself. so i put myself in charge of my own happiness, and thus gained a shit ton of confidence. i also walked around listening to ashnikko, nikki minaj, cardi b, jessi, lady gaga, basically anyone that gave me CONFIDENCE.
i would start by smiling at someone who was a shy as me. then i would slowly start talking to them. i kept the subjects bare, about what classes she took, what she liked and disliked, about homework or any events that happened at school or in the town. eventually, the awkwardness wears off. you just have to stick around until it does, and that's the hardest part. then you gain one friend! and together you can take over the world