Click File >> Open and open your PDF file in Text Speaker. Click on Speak and it will read it aloud to you.
You can also highlight any text on your screen, in any program, and use the hotkey to speak the selected text. There is no cutting and pasting required. More information about the hotkey and how to set it is available at the bottom of this page:
https://www.deskshare.com/help/ts/Settings.aspx