Advice on Extracurriculars

Hello. I'm from Bangladesh and I'm currently doing AS level. For studying uni abroad, ECA is a huge factor. Now, thinking about it I don't have much ECA or volunteering work. Part of the reason is, my school doesn't have clubs or volunteering things. I did academic tournaments and I practically went to art school half my life. But I feel like it's not enough. Can anybody suggest any ECA I could do now? Like doing basketball and learning a language...?

What subject do you want to study? If it's an academic rather than vocational course, then you need to show your interest in your subject not how good you are at basketball.

I want to do something in the physics field. Like maybe architecture or aerospace engineering? I'm still trying to figure myself out tbh.

Architecture isn't in the physics field. It is a design-based degree. Have a look at the following thread to see the A level entry requirements for architecture courses in the UK:

https://www.thestudentroom.co.uk/showthread.php?t=7361710

Thank you for the ref. But here in my country, people dont really study a type of art degree based subject separately. They tend to choose from the basic subs like maths,phy,chem,eco,and all those. The refs you suggested are for UK. Is it possible to share a similar requirements thing for uni(s) in the USA? For personal reasons ,I'm aiming for UT Austin. Additionally, I can't for sure say I might be doing architecture. Maybe I might lean towards other types of engineering like civil or mechanical or chemical.

Sorry, the student room focuses mainly on UK unis and I don't have knowledge of US university requirements. However, you might find some information on the Studying in North America forum:

https://www.thestudentroom.co.uk/forumdisplay.php?f=227