You can apply bold, italic or underline formatting by selecting the relevant text and choosing either bold, italic or underline from the character formatting menu.
If you are typing and wish to change the character formatting for the next few characters that you type, then you can just choose bold, italic or underline from the character formatting menu, without first selecting any text and subsequent characters that you type will be shown with the corresponding character formatting, You can turn off the character formatting that you have applied, simply by selecting again either bold, italic or underline accordingly from the character formatting menu.
