In high season July/August you have to be careful, there are so many tourists on the beach. So kitesurfing close to the beach is not a good idea, sometimes they call the police. :(
On the right hand side on the river (Denia side), police will say less then on the left hand side (Oliva side).
How to go there
Car park on the Oliva side, just cross the river with your gear. If there is wind bathers go home anyway. :)
Nightlife
Heaps of places to go out, Denia, Calpe or if you drive a bit further Benidorm (about 60km).