Tutorial #1 - Read the included help file.
Tutorial #2 - Try something, see what you're comfortable with and what you need to work on. Specific questions are easiest to answer.
Tutorial #3 - If you're comfortable with 3-dimensional equations and parametric equations, download the NL "Elementary" tool.
Tutorial #4 - If you want to design the forces of your ride, download the "FVD" equations for "Elementary"
Tutorial #5 - Check out
CoasterSims.com for a LOT of beginner to advanced trackwork. Read the forums there as many people have probably asked the same questions you need answered.
Tutorial #6 - Practice, experiment, practice some more.
Personally, before I ever open NL, I have dozens of notes, drawings, and equations worked out for the design of my ride. I like making sure it works before I spend weeks designing it.