For Journeylevel exam, you will need to have 96 hours of basic classroom training, or documentation of successful completion of an electrical apprenticeship program.
Its a open book test, can take any copyrighted text with you and print a copy of the RCW/WAC from the state electrical website (L&I)
https://lni.wa.gov/licensing-permits/electrical/laws-rules-policies
RCW 19.28 are the electrical laws, and 296-46B are the rules, the RWC has the what and the WAC has the how. A new version of the WAC goes into effect July 1, 2020.
Washington will be adopting the 2020 NEC July 1, 2020, and so testing on the 2020 will probably start about July 1 2020.
Subscribe to the L&I electrical currents when you can, its our monthly newsletter. There is a question of the month, and I suspect these questions are the same as on the electrical exam...so I would go back and review back questions
Information on testing from out of state
https://lni.wa.gov/forms-publications/F626-009-000.pdf
PSI is the testing agency and there is some good info there. You can test and get your certification before you move to Washington.
Depending on where your knowledge is, I would suggest studying 10-20 hours a week and do around 100 practice questions, Mike Holts Exam Prep is the best for you