Is there anything else I’m supposed to be doing apart from A-levels?

There are some people at my 6th form getting into programmes, but how do I find them? Are there any extra things I’m supposed to be signing up for? I’m just confused how people know what to sign up for, especially since most deadlines seem to have already passed.

I do biology, psychology, and English literature. If anyone knows anything extra I can do, help would be appreciated.