There is a free course called “Transition to A level Mathematics” that you can access here: https://amsp.org.uk/transition-to-a-level-mathematics-course-2024/ We highly recommend that you use this course over the summer holiday.
You will need to register for a free account on the Integral Maths website to access the course. Maths A Level students at Shrewsbury Colleges Group use the Integral Maths website - in September, you will be given login details to access all the resources.