Essays / Expository Writing ... overprotective parents (how to start?) [2]

Hi everybody, I need help in expository writting . The topic is Overprotective Parents . This is my first time writtng expository and my english teacher is no help at all . I understand that in EW there is persuasive,discussive and opinonative . Am i suppose to write one of them depends on how to the question is asked or do i choose myself ? And I reallyyyy have no idea how to write overprotective parents . I have bits here and there but not really sure how to start with a thesis statement . Thank you ~