Hey trav,
Congratulations on the new job!
Portland is a very user-friendly city, & I'm sure you'll find a lot to like there. Ditto the wilderness. Having lived in Oregon for 25+ years, I got to see some of it, but didn't nearly deplete the possibilities for backpacking/hiking. Here are some simple suggestions for openers that you can pursue further:
Cascades: anywhere along the PCT is worth a close look. These are friendly mtns, if just a little too clostrophobic with the dense timber. To deal with that, I always headed for the high peaks, all volcanoes along the crest. My favorites were Mt Jeff(erson) up close, from Pamelia or Marion Lakes; Three Fingered Jack's Canyon Creek Meadows in wildflower season, and anywhere in the Three Sisters region, especially Green Lakes. The lakes have an openness that suggests the Sierra without losing their Cascades feel. (btw- - don't forget to check out Mt Adams, St Helens, and Rainier in Washington either).
2. Eagle Cap Wilderness: the Wallowa Mtns, yes! Wild, gorgeous, remote and intimate, this small range packs an enormous variety of options for its size. For a first look, take the gondola to Mt Howard from Wallowa Lake (a jewel of a glacial lake; look for ospreys & their nests at the inlets); I think you'll be impressed. Lostine Canyon offers a grand entrance to the heart of the range, there are sizeable scenic lakes in the southern portion, and the east side entrances, grand in themselves, almost pale in comparison to what lies a little further east in Idaho. When you're here, think of them as the "lobby" of the Rockies.
3. Other possibilities: the Elk Range: a small but high ridge-crest just west of Baker that gives rise to the storied John Day River headwaters. Oregon's gold rush country and some nice destinations are here. Further west and downstream in the drainage is the Strawberry Wilderness, another small but precious alpine island amid the high desert. South into that desert is Steens Mtn, with a fantastic view across the alkali basins to the east, and the lands of the mighty MC Ranch, a real western legend.
It pays to remember to be weather conscious, especially in the Cascades, at any time of year. I spent a miserable, wet 4th of July at Wasco Lake holed up in the tent in a downpour. East side is drier, but still unpredictable in the high country.
I'm sure others will chime in here to help you (Old Ranger, where are ya?) and you're gonna find some wonderful times ahead. Happy trails!