You need to decide what exam spec you’re going to follow and then make sure you buy books etc that fit with that spec.

My son is studying Cambridge IGCSE English Language. He tried Pearson Ed Excel but found it harder so we switched.

You can go to the websites and print exam specifications off and then see which is the best fit.

I think the main specs are Cambridge and Pearson Edexcel.

I may be wrong on this, but I think you’d need IGCSE rather than GCSE as GCSE has a coursework component. It is difficult to get this marked when you home educate.

Re exams, I have booked with Tutors and Exams. They are based all over the country.

I have paid around £220 per IGCSE - most have two exams.

I hope this helps :)