A 定食 teishoku (set meal): rice, soup and a main dish, the standard lunch across Japan.
Short answer: ご飯 gohan means both “cooked rice” and “a meal”, which says a lot about Japanese food. To order, name the dish and add ください (please give me) or the slightly softer をお願いします. Restaurants follow a set script, from いらっしゃいませ (welcome) at the door to お会計お願いします (the bill, please) at the end, and every meal starts with いただきます.
The three meals
Each meal is a time word + ご飯. 晩ご飯 and 夕ご飯 both mean dinner.
Everyday food
Many common foods are written in katakana because they arrived from abroad: パン (bread) from Portuguese, カレー from English.
Drinks
お茶 on its own usually means green tea. 紅茶 (“red tea”) is black tea.
How it tastes
All five are い-adjectives, so they take くない and かった.
At a restaurant
The same exchange happens in almost every Japanese restaurant. You only need to understand the staff’s lines and say the guest’s.
Staff
いらっしゃいませirasshaimasewelcome何名様nanmei-samahow many peopleですかdesu kais?
Irasshaimase! Nanmei-sama desu ka. · “Welcome! How many are you?”Staff greet every guest loudly; you do not need to reply to いらっしゃいませ.
Customer
二人futaritwo peopleですdesuis
Futari desu. · “Two, please.”Or hold up two fingers.