Becoming a driving instructor (ADI) can be a very rewarding career if you love developing people from all walks of life, differing abilities and aptitudes.As with all new careers you do not know quite what is involved until a little research has been completed. I will provide web links and some personal thoughts on my own development since 2004.
There is an insightful ADI job preview page here.
It gives a good starting point and good for self reflection on the expectations of the job, personal characteristics and present knowledge and understanding.
https://nationalcareersservice.direct.gov.uk/job-profiles/driving-instructor
https://www.gov.uk/become-a-driving-instructor