I spent a week at Grayland Beach State Park in June and would classify as family friendly and safe. It's also teardrop friendly, most sites have hookups, and it's in an interesting part of the state (Gray's Harbor). I'd recommend it for a first timer.
It has easy to back into sites with good separation and privacy and is close enough to town that you can run out for forgotten supplies easily. Oh, and good clean restrooms and showers.
<Chas>
