Checking the brakes isn't a complicated job and, if you have the right wheels, you may not even have to take anything off the car. This mini guide assumes that you're not having trouble with your brakes. If there's an issue stopping your car then yes, you probably have a brake issue. There are three areas you need to check and we'll explain how below.
Behind your wheel that large, shiny disc is your brake disc. There should be a nice sheen to it along the outward-facing side. A scratch or two is okay but be wary if there are any obvious major defections such as a bump or a rusty looking spot.
These are harder to see with the wheel on, but peak around to the side or top of your disc and you'll notice a clamp with a pad touching the disc. Pads are replaced rather frequently and if your pads have gotten too thin (anything less than two CDs stacked on top of each other) you should swap them (learn how to do this job here).