A/A Level Chemistry & AP Chemistry vs IB SL Chemistry

Hi, I am a student already taking SL Chemistry (year 2) in my school and I want to self study AS Level/A Level/AP chemistry because of university requirements... What is the syllabus difference between these exams? Is it something possible to do or is it just too much workload? If this is the wrong subreddit to ask this question, where else can I ask this?