. After you create a new message, select the font style and font size you want from the options available in the program. Font style and font size will be displayed among other options in a strip of clickable icons at the top or bottom of the message box. Click on the font style icon, and then click on your choice on the list that pops up. Then do the same for the font size.
Create the message and enter your text. Then highlight the entire text, and click on your selections for font style and font size.
For a presentation it is best to use a “Sans Serif” font. The best presentation fonts are Arial, Tahoma and Verdana. Of these Verdana can be used as a headline font. You can use fancier “sans serif” fonts like Univers and Trebuchet but these have a problem that are not commonly available in most people’s machines.