Assuming that you're talking about the QCF levels, then the GCSE's you've completed will mean you already have a level 2 qualification.
There's no general rule preventing you from studying a subject at Levels 3 & 4 if you have not passed the prior level for that subject. When I left school I undertook a Level 4 Accountancy Apprenticeship despite not having any prior work or accountancy experience and only having 7 GCSEs.
This might be different though for individual employers or particularly specialist subjects. This depends on your chosen career/industry/profession.
Assuming that you're talking about the QCF levels, then the GCSE's you've completed will mean you already have a level 2 qualification.
There's no general rule preventing you from studying a subject at Levels 3 & 4 if you have not passed the prior level for that subject. When I left school I undertook a Level 4 Accountancy Apprenticeship despite not having any prior work or accountancy experience and only having 7 GCSEs.
This might be different though for individual employers or particularly specialist subjects. This depends on your chosen career/industry/profession.