Learn every noun with its article — el or la tells you the gender:

Comida (food)		Bebida (drink)
el pan	bread	el agua	water
el queso	cheese	el zumo	juice
el jamón	cured ham	el café	coffee
la tortilla	Spanish omelette	la leche	milk
las patatas	potatoes	la cerveza	beer
el pollo	chicken	el vino	wine
el pescado	fish
la ensalada	salad

• El agua is feminine — it takes el only because it starts with a stressed a. The adjective shows the truth: el agua fría (cold water).
• In Spain a tortilla usually means tortilla de patatas, a thick omelette of eggs and potato — not a wrap.
• Patata and zumo are the words used in Spain; in Latin America you'll hear papa and jugo.