At your table, the waiter will offer you the menu – this is “la carta”, not “el menu”. You will be asked if you want something to eat - “Quieres algo a comer?” - or what you would like to eat - “Que quieres comer?” Or if you want something to drink - “Quieres algo a beber? ” If you are not offered a menu or don't find one placed already on your table, you can ask for one - “Quiero ver la carta, por favor.”
Look carefully through the menu. Spanish menus usually have different sections. There can be a Menu del Dia (Menu of the day) where, for one set price, you can have a soup, a salad, a main course, a side dish and a dessert.
There can be a Platos Principales (Main Courses) or an Especialidades de la Casa (Specialties of the House) section listing the different dishes the restaurant specializes in. This section will usually include sub-sections like Ensaladas (Salad), Sopas (Soups), Pescados (Fish), Mariscos (Seafood), Carnes (Meat), Postre (Dessert) and Vinos (Wines).
Sometimes, the menu separately lists the Entrantes (Appetizers – sausages, hams and cheeses), Primo Plato (First Course – salads and soups), the Segundo Plato (Second Course – stews, roasts, chops or grilled food), Postre (Dessert) and Vinos (Wines).