In the world of internet, anything and everything is up for downloads including fonts. So when you would like to add to your collection of fonts for your desktop publishing software, you can simple go to the respective site and download it.
Now depending on what font for which software you select, you may or may not be charged for the download. If there is a charge for downloading the particular font then of course after the download is complete you are a given a license to use the font as you see fit for it. But this is more for professionals who require specific fonts in their line of work.
For the others who are simply looking for a funky font say to decorate a poster or for an invitation there are tons of fonts available online for downloading for free, such as the cursed text font. You will want to check though before you download them that it is not a trial based option as in free for a specified number of days and that all the characters of that font set are there, sometimes only the numbers may be available or the letters or the punctuation and various symbols are eliminated completely.