Most posts require you to be of Qualified Teacher Status (QTS) to work within a school in England.  Here are a few ways to train, depending on your circumstances.

Have a Degree

University-led training: you will spend about one-third of your time in university and the rest in school placements.
Train as you teach: on a school direct (Fee-funded) course, you spend more time learning on the job than on the academic side.
Earn a salary: Some training programmes like School Direct (salaried) and postgraduate teaching apprenticeships offer you a salary.  Again this option means you spend less time learning at university.

Don’t have a Degree

Undergraduate teacher training degree: These courses can take up to 4 years. Qualifications vary depending on the course. You could get QTS with a Bachelor of Arts (BA), Bachelor of Education (BEd) or Bachelor of Science (BSc).