FreePDF: These functions are possible in FreePDF only for newly inserted text boxes.
Select text with the Text edit tool 
and choose the command Spacing 
on the ribbon tab Home | group Character to open the dialog box Text Spacing. In it, you will find the options that can be changed:
▪Letter Spacing and Word Space
Press 
to reset both the letter space and word space to the default value 0.
To change the current line space, you can also select the Line spacing 
button on the ribbon tab Home | group Text box.