If you bought the bike from a bike shop, just go there and have them help you.
If you have to figure it out by yourself, there are two kinds of stems - "threaded" and "threadless"
I found a photo of the bike, and although I can't tell for sure, it sounds like you have threaded. Threaded stems are generally shaped like the number "7". This is also known as a "quill stem". There is a shaft that goes into the bike's head tube and thereby controls the front fork and wheel for steering when it turns. The bent part of the stem attaches to the handle bars.
See if these two links help:
First step would be to see if the one you have can be raised - either by making it stick into the head tube less or, if it's adjustable, raising the angle of the part that attaches to the handlebars. It's hard to describe how to do it, but it's dead simple and if you bring it to a bike repair shop they could do it while you wait. IF they charge you for it, it would be negligable.
There is only so much you can raise a quill stem because they have "minimum insertion" lines for safety.
If that doesn't do it, you'll need to buy a new stem but they aren't super expensive. You'd want to get one that is longer in the vertical dimension so it would come up higher. You can also get one with a steeper angle which would also raise the bars.