Does anybody know any volunteering options for upcoming juniors in high school in medicine? Or any volunteer work in general?

I wanted to volunteer over the summer, but I'm not really sure where to start. I'm looking for opportunities to volunteer in Los Angeles. I love animals, so I was thinking about volunteering at an animal shelter, but I'm also interesting in volunteering in a hospital or retirement home. Does anyone have any recommendations? In general, I think it would be nice to volunteer somewhere that could help me for my medical career/help others. I'm pretty bad at social interactions, so it would be nice if I could help behind the scenes, but if not, I'll try to be as extroverted as possible.