To become a lecturer you can do it by many ways:-

1.You can take higher level exams of Hindi like there are Pradyamika, Madyama etc and you can finish the levels of exams there to be a hindi lecturer

2. If not you can opt for a B.Ed course and that will be minimum requirement for being a teacher at Schools

3. Any field of your interest if you pursure Masters in that program then you are eligible to be a Lecturer.