Hmm, I'm not sure about longer term opportunities, but have you thought about participating in events?
One event I know about is Los Altos Hacks (https://www.losaltoshacks.com), where I was supposed to be a judge earlier this year (it has been put on indefinite hold due to COVID19). I think you can participate in hackathons (I'm sure virtual ones will spring up here and there) and other competitive events like that. Events like this, even if you don't win, are a great way to gain experience in a resource limited setting.
If your school offers it, another thing to consider are state/national science competitions. When I was in high school, I participated in building a balsa wood structure (built only with balsa wood, glue, and paper) that would hold hundreds of pounds of weight (I think ours held 500 lbs before failing?). I don't remember the name of the program, but it's similar to this one: https://www.wired.com/2007/05/odyssey-of-the-1/ . It seems like this organization called MESA (https://mesa.ucop.edu/student/) offers similar competitive events in California. It might be worth emailing your teacher and/or guidance counselor to see if there are similar programs/competitions that your school participates in (even if it doesn't, if the school will support you/your-team in participating).
I know there are a lot of unknowns due to COVID19, but I think people will come up with new ways to allow students to learn and separate themselves out of the pack. I wish you the best!
Another option is looking into the universities/colleges in your area. Most universities/colleges have special programs for high school students. They are usually announced on the university websites and your high school counselor may have more information about these programs.
Also I would check the below website. They post opportunities/programs for various STEM fields available to K-12, undergraduate, and graduate students.
Additionally if you are interested in specific courses, you can check free online courses on Coursera or edX. These offer college courses at different levels. In most cases, auditing is free. They would give you an idea about the classes and different areas within the field.
Best of luck!
Do some online research on typical careers for people with degrees in physics. I included one URL below to get you started. Do some of these areas sound more interesting than others? For those that do sound interesting, try doing some more research on what those jobs are really like and try to find people holding those jobs so you can talk with them about how they got to where they are today and what they most like about their jobs. If for example astrophysics sounds more intriguing to you, post here. It may very well be that someone here could help you connect with an astrophysics who might be willing to talk with you about her job and share ideas for internships, job shadowing or tours.
Something else you might consider while Sheltering in Place is helping with remote support of real research project. Check out the Zooniverse below for a listing of research projects needing on-line volunteer support. As of today I counted 17 open research projects there in astrophysics (measuring curvature in spiral arms of galaxies; locate and identify supermassive black holes) or geophysics (e.g. Earthquake Detective).
Have fun exploring!
Ron recommends the following next steps: