Let me know when you'll be around if you'd like to meet up.
Since it's you, you absolutely must not miss Hippo Hardware. https://www.hippohardware.com/
You can't do Portland without checking out Powell's City of Books; four stories covering an entire city block: http://www.powells.com/
Definitely visit some food cart pods. One of the best is the Belizean Chicken place: http://www.foodcartsportland.com/2013/07/29/love-belizean/
Of course, Voodoo Donut & Wedding Chapel is a must see. Just don't try to go first thing in the morning unless you want to wait in a line that stretches around the block. https://www.voodoodoughnut.com/
Walk along the riverfront on the east side, hike in Forest Park, hang out in "Portland's Living Room," Pioneer Courthouse Square. And if you're in Pioneer Courthouse Square near noon, don't miss the Portland Weather Machine's daily weather prediction: https://en.wikipedia.org/wiki/Weather_Machine
For a very short day hike, check out the Witch's Castle, a cool ruin with a fascinating history and a connection to Danforth Balch, the first man to be hanged for murder in Oregon.
It's fun to tour the Shanghai Tunnels at night: http://www.shanghaitunnels.info/
Oh, yeah, you'd probably enjoy a tour of Pittock Mansion. The building is fabulous but the tours only let you go so far and they actually lock the doors to the parts where they don't want you to go (I know this from first-hand experience), which is a very un-Portland-like thing to do: http://pittockmansion.org/
If you're interested in gardens, we have an excellent Chinese Garden, Japanese Garden, and the International Rose Test Garden.
If you'll be around on a Saturday or Sunday, don't miss the Portland Saturday Market: http://www.portlandsaturdaymarket.com/
If you drive about an hour west, check out the Evergreen Air Museum, which features The Spruce Goose, among other fascinating aviation artifacts: https://www.evergreenmuseum.org/the-spruce-goose
Of course, per capita, Portland has more of two things than any other city in the country: bookstores and strip clubs. (Yes, we have more strip clubs per capita than Las Vegas.) Now many of these are seedy affairs, but one shines out: The Casa Diablo Vegan Strip Club, http://www.casadiablo.com/, which prides itself on exploiting women, not animals. I have never been, but a list of Portland must-sees would not be complete without it. And, to put your mind at ease, none of the performers wears fur or feathers.
I'd normally say to head out to the Gorge for some quick day hikes and fabulous views, but there are no views right now because of the intense haze from all of the forest fires in Washington & Oregon.
And pot is legal here. You can't go more than a few blocks, it seems, without running into a dispensary. I recommend the gummy bears. . .