Re "I hope to ride down the west coast highway"; just for perspective, I rode much of this route, from Mexico to Vancouver Canada, over a 3 day weekend. Fourteen days will give you ample time to expand your itinerary.
First, I would travel before June 1 or after Sept 1 to avoid vacation travelers that will be on this popular route with you.
If I had 14 days, and didn't get to the seashore very often (because you're going to travel about 1K miles of it), I'd start in Seattle, head toward Astoria, Oregon,then follow Hwy 101 to Legget, Calif. From there, continue on Calif Hwy 1 through San Francisco, Monterey and on to San Luis Obispo, CA.
The route above constitutes the best of the Pacific Coast Hwy (PCH).
From there, I'd leave the coast route and either head east to Las Vegas or continue 2 hours further south to Ventura, where I'd still turn east and ride toward (Death Valley and ) Las Vegas.
PCH (Hwy 1) from Ventura south to the Mexican border is hard to follow and mostly uninteresting urban slab.
From the Las Vegas vicinity there are several amazing sites and parks that are an easy one-day ride (Hoover Dam, Valley of Fire; through Zion Natl Park to Hwy 89, then Cedar City, loop back to Vegas). I'd turn north again and travel north (Calif Hyw 395, Nevada Hwy 95 or any other route north - I love the desert) to Reno NV or thereabouts.
From Reno, pick any northbound route to Boise Idaho, Bend Oregon or Spokane Wash. Your final leg then takes you back to Seattle.
If you have to travel one-way with Los Angeles as your destination, your options will be limited as others have explained.
You might be able to rent something you'd enjoy from Riders-Share.com, but I think you have to return to where you rented it.
Best of luck. Gary