It all depends on where you are as a caster, and if you have a rod big enough. But I would hit the Sky, Snoqualmie, the Stilly and the like looking for steelhead and salmon.

I would expect that you should be able to cast 50-70 feet, and have a #7 rod or above.

If you can't cast that yet, then I would either stick to trolling lakes, until your casting can get you into 40-50 feet, then go river fishing. And if your rod is a #6 or below, then maybe you should stick to trout, at least until you are more experienced.