Hello Michele,
I would suggest creating a button on one screen to open the report. It can be any screen you like.
Let's take a look at the 'Print Preview…' button on the Invoice screen. The button contains a 'Generate Report' action on the Click Action. On your own button add a 'Generate Report' action. In the action, select your report name for Report. You can filter your report, but it doesn't look like you want to do this in your case. You have an overall case that does not need to be filtered with a current value on the screen. (Unless for example, you want to filter prices based on the customer chosen on the current screen). Select PDF as Report Type. That should be enough to see your report.
See the Print Preview actions and Generate Report sample below for guidance.
Greg