We are a young couple 24 looking to stay near a town centre but near a beach too if possible.
MB boutique hotel. Pretty central, near the beach, rooftop hot tubs and sun beds. Really nice, modern hotel & it's adults only.
If you just want the beach you will be fine. Worth reading this post though and there are many others if you do a search.
Look in the Torrecilla, Carabeo area. Both are reasonably central.
Just back and stayed in the Puerta del Mar, first visit. Fabulous friendly staff and a lovely hotel, the location couldn't be more perfect. Will hopefully return in September.