follow signposts from Ibiza Town and the airport. Parking is plentiful - much of it is attached to the restaurants, but there is also one large sand pit where cars can park at the entrance to the bay.
If you don't mind walking 10 minutes, there is a free car park at the Lidl roundabout at the entrance of the resort, coming from Ibiza Town (Google maps) The waters are shallow, safe, and great for ...