What I've found works best for me:
1) Watch the YouTube videos concerning the operation you want to perform
2) Try to replicate and/or extend the operation
3) When you get stuck, go to the help file
4) Ask questions here
Piddy goes quickly in the videos, sometimes at crucial points (like editing the track surface), which means you miss the a minor but important detail. I've always found that important detail in the help file, but sometimes forget to look and end up waiting for an answer here when it was right in front of me all along.
First off, don't worry about all the options. Lay down a short test track (or trace one in Google Earth and learn to import the flat KML). Move the track nodes around and get a feel for the interface. Change the surface material and camber and shape. It's important to be able to finish the track shapes before laying down your final terrain.
Add terrain panels for a few panels out from the track and move those nodes around. Break up the terrain groups and merge them back, hide the unselected groups, and know why you're doing this. Learn how to change and blend the texture.
With some terrain on the track edges, drive modestly on the track to learn what you want to change (add bumps, remove bumps, smooth things out). Since you didn't invest much in that initial terrain, go ahead and delete it and start over now that you've learned more.
Finish the terrain and then start adding objects. Go easy with adding objects, starting with the landmarks and then adding detail as desired. You will be amazed at how adding objects transforms the result.
Back up your projects. Copy them to CD or DVD or a thumb drive. Save different versions (First Track 1, First Track 2, First Track 3), particularly as you move to different operations, so you can more easily undo structural boo-boos (you can do some very ugly things early on without realizing it until you start a later step). Following this practice will reduce future headaches enormously.