About the location
Great places for your first day in this city with over 700.000 inhabitants are the famous Pike Place Market and Pier 55, where you can find a lot of nice stores and even a ferris wheel just beside the waterfront. Westlake Park is usually a good place to get by bus, because everything else is within walking distance or can be reached by the Monorail, if you want to get to the Space Needle.
Very popular for photography is Kerry Park during sunrise, because you have a really nice view from up there towards the skyline of the city with Mount Rainier in the background. Another great place is the southern view towards the skyline of the city with the S-curced highway, which is located at Dr. Jose Rizal Park and best during sunset.
For a daytrip, you might enjoy getting to the impressive beach of La Push through Olympic National Park. In the other direction you might enjoy Snoqualmie Waterfall or the Twin Falls, which are close to each other and both worth a visit. The region around Mount Rainier is also nearly always a great place to be.
A little bit further away are the for photographers well known Palouse Falls, which is around 4 hours away by car from Seattle. Snoqualmie is on this way too, but getting all 3 waterfalls during a single day is just too much if you want to enjoy all of them.