When I go to Chinese restaurants with my Western friends, they would ask me what to order according to Chinese custom.
If you ask any Chinese what kind of dishes make up a meal (for example), most Chinese people would simply say 'four dishes and one soup'.
I am not sure when such a concept of a meal became so popular in China, but that is what is considered as a standard meal. Of course there are many variations from family to family, and depending on the situation (for example, how many people at the table, what you can afford, and so on).
These 'four dishes' typically include a meat dish, a fish dish, and a vegetable dish. The fourth dish can be of your choice. Although this is not a rule by any means, if we have guests at home or go to restaurants, this is normally what we would order. The stable food is usually boiled rice.
And as for how many dishes we would actually prepare, we normally say three dishes for two people, six dishes for five people, and so on: always one or two more than heads. This may strike you as too many, but given that we do not have starters nor cake as desserts in China, it is not unreasonable.
Oh, and it is not a bad thing if there are left overs. Although your host would be happy seeing you finish and enjoy all the dishes, they would also get worried and think the food was not enough. If you ever get invited to have dinner with a Chinese family, never finish all the food on the table, otherwise your host will panic, go to the kitchen and start cooking again.
And I like the idea of sharing, because like this, everyone can taste different food on the table. Of course, if you do not like the idea of everyone using their own chopsticks to pick up the food from the same plate, you can always use a different spoon for each plate.
Coming back to the details of each meal, for example, during weekdays, I would prepare three dishes for each dinner for two of us. These include a slightly 'heavy' dish, a meat or seafood dish (or soybean dish for a 'vegetarian' night), one vegetable dish, and one salad (especially for spring and summer).
The cooking can be very simple and quick. But in China it is essential for each meal to include different food varieties and different kinds of taste.