Hi an welcome. Unfortunatly to complete a NVQ3 (which is needed to get JIB electrician grade) you need to be working as a sparky as it is mainly a portfolio of work as opposed to exams etc. Also as you are under 21 and have not been working as an electrician for over 2 years you would need to have on site assessments from a NVQ assessor.
The 2330 levels 2&3 are the technical certificate so as you will know are classroom based with a bit of workshop thrown in for good measure. You are then given exams (I think six exams for a level 2 and three exams for a level 3) on subjects such as Health and Safety, AC Theory etc
You could ask around or send your CV to local electricians offering to work 1 day a week for free in return for training but you need to be careful of 2 things:
1, Keep in mind most electicians will get letters/CV's from people in a similar position all the time so don't be disheartened if you hear nothing.
2, If you are fortunate to get a job with a sparky you need to know they are not taking the "Mickey", don't spend every day sweeping and making cups of tea. Yes, you will be expected to do that occasionally but if you are offering yourself for free you need some mutual respect.
If you are lucky enough to get some work you need to enroll on the NVQ and your college/training providor will give you a blank portfolio which explains all the different modules that you need to give evidence of doing. This is done by taking photos (remember PPE etc) and then writing up the job giving reference to the 17th Regs, proving you know why things are done in certain ways.
I think the long and short of it is you have to be working for a qualified electrician to he can sign your work and verify to an assessor that you completed it under his supervision. The thing you are going to find hardest is getting some work either free (or if you are extra lucky) paid. You can try to make yourself more appealing to potential employesr by buying a good set of tools and kit which I know is difficult if you are not working.
Good luck and if you need any more help drop me a message and I will do my best to help.