What are some STEM related internships for high school students?

I’m a freshman in the California bay area, and I am interested in research and internship programs related to STEM in the future. Any ideas?

The easiest opportunities to get are those that you find by yourself in your area. Are you near a university? Are there companies that communicate with your high school guidance? Start like that by looking what is available locally. Call, look for announcements, ask around.
There are research/internships opportunities that are more widely advertised but those will have a very formal applications format and they will be extremely competitive. You can find them by googling.
I ll advise you to find some using local resources.