I am trying to transfer a power point from my mac to a flash drive to work on a pc? Can't figure out how to get it to work

And make sure the flash drive is formatted as FAT32. The PC won't read anything from a Mac OS formatted drive, and your Mac can't write to a NTFS (Windows) formatted drive.

If both the Mac and PC support it, exFAT is also possible and allows for larger file sizes.

Save the PowerPoint file to a Windows' compatible PowerPoint file using the Save As option then choosing the most compatible file format.