First of all, you must give yourself a goal, what kind of university you want to enter, so that you can grasp the key points when understanding the training institution, instead of muddling through.
Secondly, there are two universities in Beijing, the China Conservatory of Music and the Central Conservatory of Music. The Fenghua Guoyun next to the China Conservatory of Music can be used as a reference. It has excellent teachers, geographical location and teaching level.
Of course, you still have to choose a method that suits you based on your own conditions