Sociology personal statement help

Hi, I'm currently trying to write my personal statement but am struggling a lot. I'm applying to sociology at Cambridge (HSPS) and other Russell Group unis. I would really appreciate advice on structuring my statement as well as what super curriculars to include. I was thinking of reading Understanding Inequalities by Lucinda Platt and doing a course around social problems or inequalities, yet to decide but probably inequalities, either on Open Learn or MOOCs, as that is my main topic of interest but I'm struggling on actually starting my statement. Thank you for any help!