Hi Matt,
Don't be disheartened by what you read here. At 24, you are young. The important thing is to learn and acquire knowledge, read as much as you can, and more importantly practice your skills. Do as much carpentry as you can, whether it be for friends & family, or, just for yourself for fun ! Making draws, boxes, whatever, you'll be learning more about working with wood than you'll be aware of. It can be a beautiful (& very frustrating at times!) material to work with.
I understand you want to get into furniture making long term and there are city & guilds fine woodwork 2 year diploma courses, or 3 year degree courses out there (Buckinghamshire Chilterns Uni / Rycotewood, etc) that would give you a basic grounding, but, you could even start on the NVQ / ICA level 2 route in wood occupations or bench joinery. They're not to be sniffed at. You may have to pay your own way through the course (they're often block release and you can take any old job just to pay your way through the course between the college weeks), but it's not hugely expensive (compared to the diploma/degree courses). You'll still be learning useful skills towards your long term goal of furniture making, like building carcasses, frame & panel doors, through and lapped dovetails, using and maintaining hand tools & power tools, working with hardwoods / softwoods / MDF / Plywood. It's all useful. If you can get work as a carpenter / joiner in the first instance, then who knows, you might find someone who is willing to pay for a one off piece of furniture made by you eventually. You have to start somewhere. You may find you enjoy it more than cabinet making in the long run !
Dig out your yellow pages / thomson local directorys and write to all the local carpenters / joinery shops explaining your situation & include a self stamped address enevlope. You may get paid next to nothing for your services, but you will be learning. You never stop learning regardless of how many years served.
If you want it bad enough, you'll get yourself sorted. Stay positive and don't get disheartened by what you read here ! Onwards and upwards !