Self-Teaching Further Maths AS Level CCEA

Next year, along with my A2s, I am planning on sitting the AS in Further Mathematics independently and an external candidate and I am just looking some tips off of people who are currently doing their A Level in Further Maths (it doesn't specifically have to be with CCEA although that would be really helpful).

I am doing my AS in Maths this year and am sitting C1, C2 and M1 in May and was wondering what modules people would recommend for AS FM if for A2 Maths my modules will be C3, C4 and S1, and I would also really appreciate it if you are doing CCEA to tell me what textbooks/ online resources you are using for the course and maybe what order you are doing the topics in? It would be very helpful if possible!

..and also just any tips in general about self-teaching would help!
Thankyou!