Don't rule out getting ALL your gear used. Most guys look after their gear fairly well and in most cases you can buy 50 cents on the dollar. You'd be surprised what $300 will get you. The nice thing is that you don't have to worry about warranty cards now so you don't have to ne an original owner. Five decades of fly fisjing still water has told me that a 5 wt. rod is your best all around rod wt. It will easily handle fish to 8 lbs. and you'll still feel the fight from a 1 1/2 lb fish.
My preferred set up is a 10' 4 wt., followed by 5 wts. That extra foot of rod makes landing fish easier. I usually only fish trophy lakes and have never felt like I don't have enough stick to get the job done with either of those rod weights. I would look for a reel that has interchangeable cassettes because you'll want a floating line, a clear intermediate line, and a heavier density sinking line. At this stage of the game you'll likely be trolling your flies so your intermediate line will probably be your line of choice. Once you start anchoring and casting, a floating line is often the "go to" line…..especially when fishing chironomids, a trout's main source of food during the ice off period.
Good quality lines will make your casting learning curve shorter. Once again, lots of barely used lines on the classifieds of fly fishing forums like FlyBC, Spey Pages (you'll see some single handers) and Washington Fly Fishing. Once again, often half price! I like Rio, but Scientific Angler lines are VERY good, as well. Lining up by one or even two line weights in the early going will make casting easier because it will help you load the rod in order to cast until you can iron out casting errors. Getting a lesson is a very good idea!
Get a decent, long handled catch and release landing net, as well, because it's so much better for the fish. If you plan on fishing out of a float tube you'll have to go with a shorter one.
Good start up rods that will give you the best bang for your buck are TFO and Echo so look for those. Once you've figure out what you're after and how much you have to spend post WTB ads on those web sites mentioned. You'll be surprised by how many guys will respond in order to help you out.
One last thing. Read as much as you can about fly fishing in the Pacific Northwest. One of the best books out there, even though it was written more than 2 decades ago, is the Gilly. Other very good authors who have written good books to check out are by Brian Chan and Phil Rowley. Keep asking questions because there are no bad ones~
BTW, one rod, one reel, and a couple of lines usually turns into MANY more down the road! Somehow they tend to multiply when stored in dark places. LOL