after Charan went to school I had started my work.

I think this is wrong... after charan had gone to school I started my work.... whenever two actions performed in the past: which action is first started in the past we should tell with "had" and the second action in "simple present tense"... if this is wrong please correct me frnds....

It's wrong. It will be:- After Charan had gone to school, I started my work.