You need to qualify as a teacher and to do this you will need a degree. (I take it your college qual's are A-level / equivalent?) You could enroll full time for a B.Ed teaching degree, or do a degree in any related subject- such as Art - and then a one year PGCE. Or you could do your degree part-time / distance learning while you work. Many schools now employ teaching assistants who are not qualified teachers, and this a good way to earn some money and gain valuable experience of the school working life. If you get your feet under the table with a school, and get a degree, the school may support you to do the Graduate Teaching programme ie you get paid as a teacher while you do the training 'on the job'.
You will need to decide broadly whether you want to work at primary,secondary or college level - there is relatively little movement of teachers between sectors once they have started off. To do this, see if you can be allowed to observe for a day or a half day at a couple of schools near where you live. This should give you some insight into which sector appeals most. You could also use volunteering in a school as a way into paid work.
But you will still need that degree to become a fully qualified teacher.