Here is your date, all will be known after this.
Pick her up pretty early on a Saturday. Take her to your favorite diner for breakfast.
Then head to Lincoln City. Stop at a winery for a tasting. Get two bottles of what she likes best. Get her a little buzzed but you stay sober enough to drive.
Stop by the plane museum/water park thing McMinnville and hit the water park for a hour or so.
Now on to your way to the coast.
Get a room in Lincoln City. (you should make reservations in advance) Something that looks out over the ocean, bonus points if it has a deck and/or a fireplace.
Walk along beach, hold hands, yadda yadda.
Take her out to a nice restaurant. Dress fairly nice.
Back to the room, open her bottle of wine, have drinks.
Then have the front desk call for the shuttle to the casino. One weekends there is live music in the upstairs bar. It looks over the ocean. Kinda cool for the coast. Drink, dance, drink, dance, drink, dance. Take shuttle back to your hotel room. (don't gamble, maybe the two of you throw a few bucks at roulette, play her birthday as numbers, shit like that. No more than 5 mins. Don't hit the slots or blackjack unless it's something she really wants to do.)
Get back to room. Make your moves.