I don't know specifics for W. Washington, but in general you will need a floating line, a full sink like a type IV, and a sink tip. You sound like you may be on a budget so decide if you will be fishing mostly lakes or rivers. In lakes you'll end up using the sinking line most of the time, in rivers probably the floating line.

Probably the #1 suggestion is join a club or go fishing with other fly anglers. That is the fastest way to learn and also start your fly collection. I don't know how many flies I've given away to new flyfishermen.