About luggage storage, it looks like there are a few BagBNB locations in Portland: https://bagbnb.com/
Medha,While we'll have a bag check at the Convention Center on Friday morning, we don't have any bag check services available on Wednesday, and the Center doesn't have lockers or other means for securing your bag.
That said - and don't quote me on this - but I think almost *ANY* hotel will let you check a bag. I was in a similar circumstance last week in Washington, DC. I went to a hotel close to my meeting and asked them to check my bag for a few hours.Maybe, perhaps, possibly, the Hotel Eastlund across the street from the Convention Center would check your bag until you are ready to head to your hotel?Hope this helps!Andrea