Different unis and different courses have different requirements, but I'm about to start a Cambridge and I got 9988887A6C. At the moment, at least, Oxrbridge count 8s and 9s equally, so it's more useful to look at it as if you got 5A* and 4 As (I got 6A*s, 2As, B, C thinking of it like that). Of course, for highly competitive subjects and for certain unis such as Oxford and LSE, GCSEs are worth more. But for less competitive high-ranking courses and for Cambridge, for instance, GCSEs are a smaller part of admissions. Law is very competitive, but there's nothing wrong with having an aspirational choice or two, a choice or two on Parr with your predicted grades, and a secure choice!
You got good grades and now it's time to focus on getting good A level predictions. Do extra reading etc for the course you want to do, write. Good personal statement and have a look at interview guidance. There's nothing stopping you getting into a very good uni, A level grades usually count far more than GCSE grades, and your GCSE grades are good!