You can download tracks that others have made, but that will tell you nothing about how this system works.
If you would like to try out the course maker, go to the main page (not GTLife) and select course maker. Pick a theme (I suggest Eifel, but whichever). Just start playing with the settings. There are only a few variables. Choose from 2-7 segments. Make each sement more or less complex and adjust the sharpness of the corners. You will find that changing one thing will change other things. Sometimes a slight change will totally change the whole track. But you can change it back and it will go back to what you had before. Once you have something you think is cool give it a try. If you find that you want something totally different, click next track.
Most tracks will have (IMO) too much elevation change. If you want less elevation change, click through different tracks until you have a small elevation change. Less than 200ft will usually give a more realistic track.
Once you have something you REALLY like, share it online so others can enjoy it.