Hi KeenPoet! So, are you thinking about whether home education might be viable, and you want to get more info to help you discuss it with your parents? You will get more replies if you post on Mumsnet's Home Ed board. (It's usually called "home education" in the UK to underline the fact that it isn't much like school-at-home.)
Even that isn't super busy. Most discussions take place on Facebook these days. Unfortunately most home ed FB groups are only open to parents/carers who are home educating or seriously considering it, leaving teens like you somewhat out in the cold when you are trying to research the subject.
To answer your question, home educated kids can do whichever subjects they like, at any age and in any order. Usually you'd do IGCSE instead of GCSE, because the latter is entirely exam-based. It can be awkward and a big expense to get work signed off for GCSE if you aren't at a school. Doing IGCSEs isn't a problem, however, because IGCSE is entirely equivalent to GCSE. In fact, IGCSE is what private schools usually do. There are just a few practical subjects which are virtually impossible to do without being at school.
There are no required subjects, but people usually do English and maths at least, because those are required for some further study and jobs. Unless you are aiming for entry to a very competitive uni course, you'll probably find that five or six well-chosen subjects is enough to get you onto the next level of education or work. A common approach is to spread exams out over several years, so you can concentrate on one or two or three at a time before sitting them and moving on to the next subjects. That is less stressful than doing a large number all at once.
You'll need to identify one or more exam centres where you can sit the subjects you want as an independent candidate. Some schools or colleges allow this - mostly independent schools - or you can use a standalone exam centre. There will be three sets of costs:
- Fee to the exam board, usually paid via the exam centre
- Fee to the exam centre for letting you sit it there
- Cost of whatever method you use to learn the material, such as books or tutors or online schools
If your family can't afford that, an alternative may be to do some GCSEs for free at college. Some have dedicated 14-16 programmes, or are willing to take under-16s on courses alongside older learners. Or you can wait until you are over 16 to do them at college. Colleges will usually offer a set of "catch-up" GCSEs for people who didn't manage to pass them first time. However, the subjects on offer at college will be quite limited compared with what you could choose at school or at home. Also, you may find your fellow students quite demoralised due to having struggled academically. Still, it's a fallback option.
Hope that gives you some ideas to get you started!