Hi and thanks for your question about planting potatoes. According to the Oregon State Extension service:

Potatoes are a cool-season vegetable but are sensitive to hard
frosts. Cool, moist conditions favor the period when tubers are forming.
The optimal range for shoot emergence is daytime temperatures of 68
degrees F to 72 degrees F. The optimal range for tuber formation is when
the temperatures are in the 50- to 60-degree range. When night
temperatures are above 68 degrees F, tuber set is reduced and above 84
degrees F, it is inhibited.

It's wise to plant in raised rows or raised beds to avoid rotting.

For growers in the Willamette Valley, daytime temperatures between 55
degrees F and 60 degrees F are the best time to plant. ...
You can cover the ground with plastic for a couple of weeks before planting
to warm the soil and encourage it to drain well. Also, consider covering
the emerging plants with a row cover (either Remay or plastic) at night
to protect against insect attacks and frost.

As for sunlight, basically, the more the better. They can grow in part shade, but they really need at least 6 hours a day, as the top green part that feeds the tubers has to make it's chlorophyll from sunlight hitting the leaves.

Here's the full article with more than you might want to know about growing potatoes in the Willamette Valley!
https://extension.oregonstate.edu/gardening/vegetables/growing-potatoes-willamette-valley