The purpose of this research study is to test a new program called Pain REsilience Promotion for Youth (PREP-Y). This program is designed to help adolescents with chronic musculoskeletal pain (pain in muscles, bones, or joints that lasts more than 3 months) become more physically active and better able to manage their pain. The program includes four weekly virtual sessions that teach skills related to resilience, such as how to stay motivated, build confidence, and cope with pain. Participants will complete surveys and physical activity tests before and after the program. Participants will also wear physical activity monitors to track their activity levels. The goal of this study is to learn whether the program is practical, helpful, and acceptable to participants, and to prepare for a future larger study.