Our go-to is The Stanford Inn by the Sea. It’s pricey, and not bookable on points or on the UR portal but it's a splurge well spent. The main building is a crescent-shaped lodge with rooms that open out to decks facing their beautifully landscaped gardens with views all the way out to the ocean. We actually spent the past 4th of July weekend there, and I enjoyed lovely, relaxing afternoons on the deck, reading, and watching the hummingbirds flit between flowers, usually after a morning hike. The rooms are paneled in pine and have fireplaces that give it a really rustic feel. Cell service is spotty, so it's a nice chance to put away our phones. The room rate includes breakfast every morning at their onsite vegan restaurant, The Ravens, an afternoon dessert, coffee and tea, as well as complimentary bike rentals from the next door Catch a Canoe & Bicycles Too on the Big River.
Another extra splurge we thought was well worth it -- We did a bioluminescence tour with Catch a Canoe one summer (before the kiddo), that was truly magical. A guide took our group up the Big River on a canoe and we could see bioluminescent plankton light up with the strokes of our paddles and the movement of our canoe. The guide also timed our trip so we could see the passage of the ISS in orbit above us. I don't know if Catch a Canoe still runs these tours, but they only happen on moonless nights during the summer months, so there are only a few opportunities every year. You may need to call well in advance to inquire and book, because when we did it, reservations were filling up fast. (I think you can do something similar closer to the Bay Area up in Point Reyes and Tomales Bay.)
Mendo has some cool shops, and some really good restaurants. We really enjoy Cafe Beaujolais and the restaurant at MacCallum House in town. We didn't spend much time in Fort Bragg last year, so I can't comment too much because things may have changed. Glass Beach is right off Fort Bragg. It's a fun stop. You'll find lots of people picking sea glass, even though I'm pretty sure you're not supposed to; and I'm surprised that after all these years of pickers there's still a good amount of sea glass that washes up onto the beach. You'll find white and brown glass is abundant, green glass is around too, but blue glass is pretty rare. The area has a few tide pools too, so it's cool to walk and look for crabs and other little sea creatures.