It's not as simple as applying to a MPL program with CTC. Competition is fierce and you will need to stand out. Everyone has GCSEs. Whilst you're still at school/sixth form get out there and take part in as many activities that you can that will help your application stand out.
I'd say most of the theory is fairly straightforward to understand, just there is a lot of it to learn and in many cases it is remembering facts.
I also think a bit more effort is required on your part to research all possible ways to enter the industry, what pitfalls you may encounter and how you could potentially overcome these problems. Your Dad's knowledge would be an excellent place to start!
Good luck.