I can't explain how to do this from scratch b/c that is much too involved. The easiest way to get started is to use the report wizard to create a new report and follow the wizard to select the data source and pick the fields to display. Once you are finished then you can re-arrange the fields to your liking. After that, choose File > Export > Export Report to export it to PDF (or Excel).
If you plan on writing more reports, you should check out my book
Crystal Reports Encyclopedia. I have a lot of tutorials that walk you through all the steps of building reports.