Choosing a major either goes one of two ways: either you completely know what you want to do, or you don't.
If you know what you want to do, then go for it 100%. Get into the department as much as you can, and make as many connections as you can that will help you once you have your degree.
If you don't know what you want to do, don't worry!!! My suggestion is to try a bunch of classes and see what catches your eye. Likewise, if you love doing something but don't know if you could make a career out of it, go take a couple of classes in that field and talk to the professors about your reservations.
The most important advice is this: Talk to your advisor. If you have an idea of what you want in life, that's great and they can help guide you on that path. If you don't have any clue what you want your major or career to be, then they will help you to figure it out before you have to declare your major.