What forms do I need to get more time with my child and support modified when there is already a court order regarding a parenting agreement?

You will need to file an Order to Show Cause (court form) requesting a modification of child support and modification of visitation.  With the Order to Show Cause, file a supporting declaration signed under penalty of perjury.  Your supporting declaration states the facts supporting what you have requested in your Order to Show Cause.  When you file the Order to Show Cause, the court will schedule a hearing on the issues you have raised.  When you file your Order to Show Cause and supporting declaration, file a proof of service.  The proof of service verifies the date of mailing your documents to your ex.  You can either use a court form proof of service or you can write your own.  If you write your own proof of service, it just says that you are at least eighteen years of age and the attached documents were sent via first class mail unless stated otherwise to __________ (name and address of your ex) on __________ (date).  You sign and date the proof of service at the bottom.  The date you sign should be the same as the date of mailing and the same date you file your documents with the court.