Yes sorry forgot to.mention air BnB !.it’s a very good idea and we use frequently when we visit Denia In spain for the holidays . The beaches are clean and it’s very family orientated but an.hour from.valencia
I regularly use AirBnB and as a single mum it works out the cheapest each time. You can sometimes arrange an airport transfer with the host and save ££’s too. Also, by getting a small apartment or room with en-suite in a family home you have great local knowledge and guides for you and your little one (as well as adult company for you and friends for your son).
We like to go to the south of France/north Spain as it’s not too hot for my little one to enjoy herself, has lovely beaches and there’s plenty for all ages to do.