Hi Vincent,

Most of the badges have a description on them that explains how one could earn them. The exception is the Black Hole Badges because they are meant to remain secret. Nobody knows how to achieve those. 

You may see badges on other accounts that you can not access and that is because many badges have been discontinued.

Let me know if you have any more questions.

Like what Lexi said, the badges (except black holes) have descriptions on what you need to do, Some are easy, some are hard, some like Artemis are impossible because KA doesn't have 7,500 skills to master, Theres also challenge patches which are easier to start of with if your starting out.