One of the easiest things you can do with a miter saw is cut a board to a specific length. Boards are typically available in 8 foot lengths, so you'll need to cut it down to the sizes you need.
2. Angled Cut
An angled cut (mitered cut) is where this tool gets its name. A miter is an angled cut made across the width of a board. A 45 degree angle is one of the most popular angles to cut, but the miter angle can go up to 60 degrees on the right side and 50 degrees on the left. The desired angle can be easily set using the Miter Gauge on the tool.
3. Beveled Cut
A beveled cut is performed by angling the blade in the vertical direction. I don't use this feature much on my miter saw, but it's a good way to make decorative and functional cuts for moldings, picture frames, etc. Setting the horizontal angle (miter) and the vertical angle (bevel) is considered a compound cut. I typically use the table saw for beveled cuts.
There are other features this tool has, but I won't get into them now. These 3 basic features of this tool are great to have whether you're a homeowner, DIYer, or beginner woodworker.