Years ago I started the planning process to make that trip, but I just didn’t have the support people I could trust to make the logistics happen. Such as making sure the food and supply drops show up on time at the post offices you’ll pass when you cross highways.
So, the only recommendations I have is to take lots of weekend trips to get the details and kinks worked out with your equipment and food. Use the same trips to break in a couple pairs of boots. Try to do your practice hikes in as much different weather as you can, since you’ll be starting out in the snow, then into the hottest part of summer, and when you get to the PNW you may or may not get pissed on every day!
I hope you have a safe trip that provides pleasant memories for a lifetime. That’s one of the few things I regret not doing when I was young, healthy, and had few responsibilities.