Hello! I'm making a quick post today about my current situation. I'm looking to teach myself high school mathematics and don't have a clue where I should start. I was kicked out of any meaningful education at an early age due to my confrontational attitude growing up. I was always good with mathematics and fascinated by the subject.

I'm in the UK and would like to get myself to a high school level of mathematics (GCSE) before progressing onto higher levels. I'm planning on paying to sit the exam around jun next year. The problem is that I have no clue where to start looking.

Does anyone know any good online resources that I could use to study and achieve a basic understanding of mathematics? How long would it take the average person to grasp the fundamental concepts? Thanks in advance.