The correct answers are I am having a wonderful time at this new cafe. and The owner has three more restaurants in the city.

Some verbs can be both state and action verbs, depending on their meaning.

When have means "to experience" or "to eat/drink," it is an action verb and can be used in the present continuous (am having a wonderful time).

When have means "to own or possess," it is a state verb and must be in the present simple (has three restaurants).