My opinion (and we all have one), is that for a young'un starting out, and being in FG, the Wilson is your best bet. First, it has great runs. There's also more bank access -- find any sort of deep hole, or even any sort of medium-depth run with moderate current, and there's fish there. Also, being a novice, people seem more tolerant of others on the Wils than the Poor White Trask.
But, if you're without a boat, you can't chase fish - you have to wait for them to "come to you." The timing is always different, but for the most part, sometime between late September and late October (usually closer to the latter), the fish will come after heavy rains. You want to watch the river level (I think it's available at the top of this forum, and many other sites) - after the rains start to come, go a day or two after the river level comes up 1.5 feet (that's what the Old Timers used to tell me when I was young and learning, seems to hold true). Immediately after a heavy rain, the water will probably be brown and roily (aka "blown out") and full of leaves. But on the first rains, it clears quickly, and usually the next day is a party. Fish will be all the way from tidewater (which is more or less at the base of the hills where the Coast Range meets the plain... the straightaway on the hiway before Tillamook) all the way up high (Jones Creek and above, although they seem to thin out above Jones).
Chuck a bobber and eggs. Or sandshrimp. Or drift either bait. Or toss spinners in sizes 3-5 (depends on the water level and clarity). Toss spoons. Do what you feel comfortable with, since fresh incoming fish aren't really that shy about biting. Once they've been there a couplefew days, they can be picky. Timing is almost-everything. Once the fish come up and start holing-up, then the couple of hours after first light are your best friend And some here will probably bash me for this, but once the water clears a bit and fish settle in, contrary to popular opinion, "settled-in" chinook are indeed line-shy. I've yet to meet the upriver chinook on the Wilson that I couldn't get with 8# mono. Lost a few to bad knots (which should NEVER happen, but does) and snags and whatnot, but never because the fish was too big for 8#. It ain't the Columbia.
But the most important thing you can do is keep your eyes open. Find places (there's a buhzillion on the Wilson) where you can sit above the water (if it's clear enough) and watch the tailout. Watch how they come up. Watch what they do when they come up. Watch where they like to navigate the river. You're probably not going to fish the stream for a season then call it quits, right? Learn the place. Just because no one is fishing a spot, doesn't mean it doesn't have fish. Conversely, just because there's a bunch of people, doesn't mean it's the best spot. And just because "everyone is fishing that way," it doesn't mean it's the best way to fish. Be your own man - lacking an Old Timer to teach you, the School of Hard Knocks is a great way to learn to chinook fish. I never had a good mentor, and my mantra was always "buck convention." Now, I do pretty well... took a while to get there.
Find a fishing buddy, get out there, and enjoy every minute of it... I have, and hope many more can reap the rewards of such a fun fishery.