Extracurriculars

I’m currently at almost at the end of Year 11, about to take my IGCSEs. I am concerned about next year and what extracurriculars I should start working on so I can build a strong university application as I am aiming for the USA.
Any subjects for A-levels are History, Maths, Further Maths and Physics. I am really interested in history, economics and politics but also enjoy physics and stem-based subjects.
If anyone has any recommendations for things I can start doing for my CV that would be great!
(also PS if anyone knows any good physics books I can read to get more interested in it that would be great, I just don’t really know where to look)

Hi, I'm in the same position as you- just about to do GCSEs! I'm gunna be taking maths, further maths, physics and chemistry, so quite similar to your subjects I guess. I'm also aiming for a US uni, but I think I want to study straight physics. For your CV, you could look at some volunteering or community work cuz American unis like that, I think. Or maybe you could do some teaching or something, for volunteering?
I have read quite a number of physics books. It really depends what aspect of physics ur into - if you're more particle physics, or astronomy, or even engineering! Let me know and I can recommend some

Thank you so much! To be honest i have no particular preference, I need to find a specific field I am more interested in. Could you recommend to me a variety of books you liked, I don't mind which area of physics it's in really. But i would also appreciate engineering books as well!