The most direct route into this job is through an apprenticeship. Another option is to do a level 3 diploma course in something like Health and Social Care. After that you can start an apprenticeship or go for a normal job.
For either option you will need to demonstrate that you have had some experience working with children so you should try to do something on a voluntary basis at a local school, nursery or youth group.
If you would like to research vacancies on apprenticeships you should visit the official Find an Apprenticeship web site and do a search using "teaching assistant" as your keyword.
For finding possible full time college courses you could visit the site of your local FE college or do a search on UCAS Progress or on this official site .
Hope that help!
- Posted: 11/08/15