How can I learn the vocabulary needed for the exam?

There are a number of different ways one can learn all the vocabulary that's needed for the exam. 

The most common one is to go to the back of the textbook, where the glossary can be found, and read the words aloud, write them, or cover one side of the list up. In this way you will not just learn new words but also revise the ones you already know. I would advice to go through the vocabulary list at least once a week. 

A different way can be flash cards. You will write on one side of the card the Spanish word and on the other side you can either write the English word or simply draw a little image. 

A very useful way is to test other people. Just ask a couple of words to a friend a vice versa. This is usually a more entertaining and easier method. 

Lastly I personally like writing the words I don't know, along their translation, on a sticker. Then I'll stick these around places I usually go; such as the mirror, the fridge, desk, etc 

Nevertheless; everyone has very different ways of learning and you just need to find the one that suits you best. Moreover; the secret is to learn them since day one!