You should contact a local family law attorney to discuss your issues with. You can also consider the self-help center, but they will not be able to give you legal advise and you have multiple issues (a prior judgment with a statute of limitations issue to set aside; a dvtro that was "never served" and child support from 2011. Hire a local attorney in your area who focuses on family law issues. The Los Angeles County Bar also has a referral panel of qualified family law attorneys. The number is (213) 243-1525. Good luck.
You are welcome to contact any of the attorneys here on AVVO for a consultation. Many of the lawyers on AVVO offer free consultations. The attorneys, however, are not allowed to directly solicit business from the people who post questions on AVVO. Therefore, no one can respond to your "question" by stating they will represent or help you. Good luck.