As stated above, the "Tool" icon will get you to the options menu to load charts
The owner's manual is a stand-alone document available online:
You will need to bounce back and forth between a browser window with the manual open and the actual CPN program. It can be a bit tedious, but the manual is pretty good. There are 2 different sections of the manual that discuss charts - you will need to read both of them before loading the charts.
Once you have charts loaded, just fool around with the program. You really can't hurt anything, and it is the best way to learn. It is quite a powerful program.
Edit: Don't know why the link isn't live, but you can cut and paste into your browser tab.