Although it has tons of visitors on an average high-season day, Carmel's city beach is a relatively long beach, so easy to get away from the people and claim your own quiet spot on the sand. If you walk to one end, you can enjoy watching the golfers on part of Pebble Beach's links.
Suggest parking in a nearby neighborhood and walking over to the beach if you can - parking in Carmel can be a challenge generally, and particularly near the beach during the high season.
This beach is also dog-friendly! Happily, everyone seems to pick up after their pooches.