Legzira is located around 3 hours driving south of Agadir. Unfortunately, public transport to this beautiful place is not ideal. You can take the CTM bus to the closest city: Tiznit. From here you will need to find a shared taxi (taxis that fit 6 passengers) that will take you to either Mirleft or Sidi Ifni. From here you will need to take another taxi to Plage Legzira. However, once you get there, it will be difficult to find transportation back.
This is why I would recommend getting either a private transfer (expensive) or to rent a car. In this way you can drive in a relaxed pace and stop whenever you want. We rented the car for two full days and left on a Saturday morning. We arrived in the early afternoon and went to Sidi Ifni by car for lunch. On the way back we stopped for lunch and a walk in Tiznit.
Place Outa El Hamam is the perfect place to try out a glass like this as you will have a nice view on the busiest square of Chefchaouen.