午餐(wǔ cān) - lunch, midday meal in Mandarin

午餐 is lunch, and it belongs to the tidy 餐 set: 早餐, 午餐, 晚餐. Alongside it runs a second, more everyday set built on 饭: 早饭, 午饭, 晚饭. The meaning is identical.

The difference is register. 餐 is the slightly more formal word, at home on menus, school notices, hotel signs and anything written down. 饭 is what people actually say to each other: 吃午饭了吗？ sounds natural in a way that 吃午餐了吗？ does not, unless you are in an office or a restaurant.

The verb is 吃, not 有 or 拿: you 吃午餐. And note 餐 also does duty as the measure word for meals in 一日三餐 (three meals a day), which is a useful phrase to have ready.