I love this one because of the red and blue umbrella, the pink one creating the orange shadow, the grandma in the front :)
I also love the sand. It's real and loosely painted. Sand color is one of the most difficult colors, especially in Summer. It's both warm and cold.
It's a literal combination of toned-down dark yellows, bright highlight blues, some dark elements in it, either a blue/purple kind, or greenish shadows, sometimes dark brown yellows in. And then decide how you're going to paint the far away sand compared to the front. The rhythm of this one, it swings. You're lucky when it all works out, it doesn't happen always.
I teach about painting Seascapes in ► Seascape Beginner that's here and an online course more specific about Summer seascapes, figures and parasols is this one: ►Painting Summer Seascapes find this here.