Flight
Seattle has two airports. Sea-Tac is the main, international airport. Paine Field is a smaller, regional airport about 25 miles north of Seattle. If traveling from Tennessee, there are direct flights from Nashville. From Sea-Tac, you can take the Link Light Rail into the city, rent a car, or uber. From Paine Field, rental car or uber will be your best mode of travel.
Travel Note
There are many amazing places to stay in Seattle while you're here. The wedding is in the Fremont neighborhood, which is close to many other areas in Seattle. Downtown hotels will give you close access to travel destinations, such as Pike Place Market, the Space Needle, and the Seattle waterfront. Other neighborhood suggestions: Fremont, Capitol Hill, and Ballard
Train
Link light rail is the cheapest and easiest way to travel from Sea-Tac airport into downtown Seattle. Follow the signs from baggage claim to light rail. Board the University of Washington train heading north. It will take about 40 minutes to travel into downtown.