You can custom build your own airfield if you want, complete with planes and cars on the ground, buildings wherever you want them.
You also have the option to remove anything you don't want, and still keep the original field. You just edit and save as...
give it a name like 'open field'. You'll always have the open field to fly in, plus you'll still have the stock airport with it's given name. That way, you won't lose anything.
You can also scale up the size of the planes (I do all of them at 2X) but you will also need to adjust the physics. Again, you can't edit the original file, but you rename it ie. Cessna 172R as Cessna 172R-2. That way the original plane is always there to start over again.
The owner's manual is a .Pdf file that I printed out and it's 325 pages. (I recommend printing odd numbered pages in reverse order, then flipping it and doing the evens)
You really don't need it unless you really enjoy designing some extensive fields, or totally changing the physics of a plane to fly like a real one instead of RC.