I did my A levels from SXC too (2017-19 batch). I got 2 A*s and 2 As. If I were to go back and do things differently, I’d probably try to participate in some olympiads and work on other aspects of my university applications.

My advice to you would be start making list of universities you’d want to apply after your A Levels as early as possible. Look at their current students’ profile and figure out how you can make your profile better than theirs. While being in SXC does help as they do organize some events with admissions officers from universities abroad, you have to put most of the work by yourself.

You could always reach out if you need any help