The tests aren't easy- if they were, most students would not be motivated to study and they wouldn't learn as much.
Many students greatly improve their scores after a bad start.
First thing to do is find out which questions you got wrong and understand the correct answers. The exam key will be posted in the display case opposite room 244. When you get your test back, take some time to examine the key. Try to judge whether you were unprepared, or whether you actually had the information to choose the correct answer and just didn't think it through. If you find that you simply weren't prepared, the chances are that you need to spend more time studying- maybe a lot more.