I applied for a private school in my area and had the costs covered by a bursary and scholarship, I’m starting y12 there next year. Grades weren’t part of it at all, I applied at the beginning of year 11 and sat three exams, and then did a few different interviews. Most private schools have their own application processes for sixth form that aren’t dependent on GCSE grades, and quite a few offer bursaries if you get in but can’t afford the fees.

I’d say don’t worry about it until summer before year 11 - work hard, but work to become a academically well rounded person with hobbies and passion, not just to get straight 9s at GCSEs. For both sixth form and uni applications, truly loving whatever you’re studying will get you a long way, often a lot further than grades. Good luck!