Taking an exam to stay on my college cource

About 6 months before I took my GCSE's (the ones this year), my school stopped our year from doing GCSE IT and we just concentrated on our BTEC IT (we were doing both simultaneously but due to some poor results- which doesn't include me, we stopped GCSE IT).

Because we only did first BTEC, my college is not sure I am capable of the A level course I want to do. The course itself has maths, physics and IT. They are willing to put me on the course but I have to score 80% or above in tests that are happening within the first 6 weeks of the term.

Getting to the point of this post, I would like any sort of advice for difficult topics and concepts for both GCSE physics (because I took IGCSE physics) and GCSE IT. Some help on early topics on A level maths, Physics and IT would also be appreciated.

Thanks in advance for any help given.