Collocations are words that go together. For example "Watch out!". Watch is a verb and out is a preposition (voorzetsel). The person saying this wants to warn you about something, probably to make sure you don't get hurt.
There are also collocations related to travel. The two pictures below give you multiple examples of a collacation, including an illustration and a sentence in which it is used. Take a look at these photo's. You will be practising with these collocations, and others, in the upcoming excercises. Since it is still practice, you may use your book or a dictionary. But try to do it without help first.