Has anyone had any experience or does anyone know about any online summer programs for high school students interested in getting credit or gaining knowledge for computer science?
Look into your local community college. I know someone who took CS I at the community college over the summer (summer before his senior year) and he really enjoyed it and learned a lot. They likely have online courses available, too. You can inquire about how to take a college class as a high schooler, at my local community college it’s called the challenger program. It may cost a few hundred dollars, but nothing close to what you would pay at a traditional school.