Microsoft Office is one of the most ubiquitous packages available for organizing and sharing information. It's most likely you have PowerPoint on your computer. There are versions for both Mac and PC.
My only advice is that you run through the presentation and figure out what you want to say: awkward pauses when you search for words or misspeak. There's a notes window you can use to organize your ideas. My trick: when I run through the slides, I turn on voice recognition and create a script to use for when I "go live".