First thing you must consider is your surfing skills. Be honest about your skill assessment since some boards are easier on the learning curve.
If you are just starting out, a longboard or foamie / softboard would be ideal. This kind of board offers the best stability. Though they are not as maneuverable, but that should not be you concern if you are just starting out.
For intermediate surfers, you can now select a wider range of surfboards. A good addition to you choices is fish surfboards and shortboards.
Expert to professional levels have the enough skill required that they can experiment with different kinds of boards to optimize their natural abilities.
Another thing to consider is you actual weight. You weight has a direct effect on how the surfboard affects the water. The general idea is that the more you weight, the thicker and wider your surfboard should be.
Choosing the right surfboard for you is also largely dependent on your height. As the height becomes taller, the surfboard also needs to be longer. As a good rule of thumb, the surfboard should be at least a foot longer than your actual height. Though surfers with intermediate skills and above can safely break this rule.