Some schools may not necessarily arrange for students to complete all these subjects in their sophomore year. Chinese and math are likely to be arranged in senior three.
Of course, if you consult with the grade leader, you should be allowed to attend all the courses.
HKCEE is extremely simple. If you don't ask yourself to get an A in every subject, then read HKCEE's book and recite the original question.
If you want to get excellent grades, I suggest you learn politics well.