WA courts ordered father to pay child support in WA state, child lives in AZ, what state should the parenting plan be filed in

If a Washington court ordered your boyfreind to pay support, then there is already an active case in Washington. Without more information, it is difficult to advise you since Washington would still have original continuing jurisdiction to make a child custody determination if there was a previous court order in Wa. If not, then Arizona would be the appropriate state. You need to gather up all of your paperwork regarding the child and confer with an attorney. Your case falls under the authority of the Uniform Child Custody Jurisdiction Enforcement Act which can be quite complicated to apply and decipher.