My only advice is study the hunting regs and firearm laws, I do it every year since I hunt multiple states and can't seem to keep them straight. WA has a fairly heavy set of regulations and limitations, deer is better than elk but it's still going to be substantially different than what you were used to.
Evidence of sex, evidence of species, access rules for public and private, right licenses, right weapons, what roads you can drive, where you can park, firearms rules (what you can legally own, loan, borrow, definition of "loaded" in vehicles, CCW, etc), plenty of stuff that can trip up a guy trying to stay legal.