With this being said, there has got to be a reason why you want to learn insults, but remember that your reason should never be to make someone else feel miserable; at least not for a very long time.
People use insults and jokes all the time. There are even social events arranged specifically so that people can throw insults at each other for entertainment. You may not necessarily be aiming to participate in such events, but insults can still be used to shut someone down. They can also lighten up dull and boring situations if used properly.
You'll have access to every type of insult; Insults for arrogant people, insults for stupid people, ugly people and more and much more.