Divorce, child custody, alimony

Hello sir/ Madam, I would like to seek a divorce from my wife. We have been married for 11 years now but living separately since September 2019 as initially she faked her mental illness and later on she had an extra marital affair. After her first affair I reconciled for my kids future to avoid a broken family. However she still went ahead and pursued another affair with second person after 3 years. Please note her first extra martial affair person had moved on and gotten married elsewhere. Now she's still faking her illness and always black mailing me, emotionally and verbally abusing me. I would like to now file a divorce for sure and get my son's custody of 6.5 years old. I was married in Lucknow at my in laws family house and marriage was registered in Jodhpur municipality. Please help me: 1. Where divorce can be filed Jodhpur or Lucknow ? Filing a divorce by me earlier than my wife files for divorce, will I receive first mover's advantage over another? 2. How can I make sure I receive my son's custody? 3. How can I know how much lump sump Alimony I might have to pay? Should I transfer my property (not co—owned by my wife) onto my parents name? Best regards, Karan Singh