Was literally just there last weekend and would recommend the following at Olympic:

• Ruby Beach - Iconic views on the beach
• Kalaloch Beach - Tree of life is here and Beach 4 (on Google maps) has amazing tide pools
• La Push - Similar to Ruby Beach with beautiful land masses rising from the ocean and the Hole-in-the-Wall is on the north end (need to have low tide to get close/best view
• Hoh Rainforest - Hall of mosses is an amazing and short .8 mile walk that is endless amazing views. The Hoh river trail is also a great hike afterwards that you take as long or short a walk as you want (it's 17miles long) but there's a sweet waterfall at the 3 mile mark
• Lake Cresent - Marymere Falls on the south side is a 15 minute hike to see a really great waterfall and the Devil's Punchbowl on the north side of the lake is a 20 minute walk along a paved former rail line (the punch bowl itself is 2 min off that trail but super easy) and the colors of the water when the sun hits are fantastic
• Sol Duc Falls - Amazing waterfall that is everything great about Olympic National Park and is only 1 mile from the parking lot

Just know that the distances between some of these places and the fact there's no road (thankfully) straight through Olympic means there's a good amount of driving so factor transit times into the day.

For Forks specifically the restaurants in town are all stupid expensive for what you get (and midling/low quality) but we really enjoyed the Westend Taproom as the beer selection was really good and the paninis there were tasty and we also enjoyed the Golden Gate Chinese restaurant for a quick bite. Multiple coffee huts to get a drink in the AM and there's a good coffee place in the combo grocery/hardware store too.

For Twilight I would only really recommend going to La Push but also the truck from the movie (and the truck described in the books) are both parked at the Chamber of Commerce at the south end of town and the Chamber also has some cool stuff. Otherwise the house in Forks is not where they shot the movie (but it's the location/description in the books) and is close to the main street if interested.

Hope this helps, have a great trip!