priestleyre
If you are a serving airman you do not need A levels to apply for a commission. You just need the relevant GCSE's. There are plenty of opportunities for gaining further qualifications once you are in the RAF using the various learning credits available to you through the station education centre, if you are willing to put in the work in your own time. I work with a guy who has gained a degree doing this and I have used the enhanced learning credit myself.
That said, if you join as NCA just as a route to commission you may be disappointed. It is still very competitive and you will be required to serve a return of service as NCA before you even apply.
There are no shortcuts to a commission, if that is what you want then study for A levels and apply when you have them. If you want to be NCA then come on in its a great way to earn a living.