Just like you,your british pen-friend is learning school and doing to college this year.write a letter in which ask him/here: what he should do to go to college.what career he has chosen.what he is doing to to realize his plans.what you should do to get to university in your country.

Dear friend,

I am writing to ask you about your college enrollment process. Had you already passed all the exams? Does your college have any specific or unique requirements for new students? Also, I know you are very good at math, but you have never told in which specialization you are interested in. Did you choose finance or another field of economics? I think to choose a career is a very difficult decision, and I hope you have a well-prepared plan to follow.
For example, in my country to enroll for a university programme you have to pass school's exams which are obligatory for everyone and also write some kind of tests in university to prove your knowledge.
Anyway, I hope you are doing well.

Best regards,
Ivan