Guincho has a wonderfull beach that ends on to the mountains.
You find here a nice beach bar.
There is 1 hotel at walking distance, but if you want some animation, you can find everything in the town of Cascais at 10km: restaurants, bars, beach, cinema, shopping,..
Lisbon is only half an hour dive and there a more places to visit at less than 1h; Sintra, Obidos, Ericeira,..
Guincho has a consistant (hard) wind in summer and a wonderfull wavespot.
For kite beginners there are lessons organised by boat.