When going out food shopping we discovered that many grocery stores are closed on Tue or Wednesdays. Even our favorite Bar Tracks and Travelers was closed on a Wed Night. There were still some shops open however. The open markets located near the train station had plenty of meat, poultry, and produce to sell on these days.
At the Belgian Coast you can rent a deck chair for half a day or a full day. It's nice and easy if you're only staying at the beach for one day. If you're staying at the coast for a longer period, you can rent a beach cabin. It's comfortable for all your beach stuff (deck chairs, parasols, beach stuff for the kids).