If you were married, you file a Petition for dissolution. If you are not married, you file a Petition to establish residential schedule. In both cases, trial es set 11 months after the date of filing in King County. I think you need to hire counsel because from what you have written, you do not have a good grasp of what is involved with what you are proposing.
Please note that THESE COMMENTS ARE NOT INTENDED AS LEGAL ADVICE and are for informational purposes only. This response is not intended to create any attorney-client relationship and is only based on the limited facts given. The response might change should additional facts be learned and should not be relied on as legal advice. It is recommended that you consult with an attorney who can properly assess the situation, as well as all pertinent facts, prior to taking any action based on the foregoing statements
You indicate that you are dealing with an "ex," here, so if this is not someone to whom you are married you need to file the appropriate paperwork to establish a Parenting Plan and Child Support. The Washington Law Help website has several information packets that contain the forms you will need and instructions for how to fill them out, how to serve and file service, etc. www.washingtonlawhelp.org. But the other issues that you mention here hint that you might need some legal help along the way. If there are reasons to believe that the Court should limit your ex to supervised visitation, you will most likely need to have a Guardian ad Litem appointed in order to investigate both households and make a report to the court regarding the best interests of the child. Additionally, many courts have Local Rules which limit the number of pages of Declarations and supporting materials you can file, and you will want to have someone help you along the way to make sure that you present your information in a manner that will make the most sense and be the most helpful to the Court.
You should definitely try to book some time to sit down with an attorney, at least to get you started in the right direction. Booking time with an attorney to have your questions answered now will save you a great deal of frustration in the future.
Please be advised that the above neither constitutes legal advice nor creates an attorney-client relationship. It has been provided for informational purposes only.
You definitely need a parenting plan. Agreed or not, you need to file a Petition to establish one. The Petition is either part of a divorce or separate action.
I've attached a link to get the forms. There is also a King County Family Law Court Facilitator to help. LawHelp has instructions. CLEAR can help get low cost help if you meet their income requirements.