Question: 
I'm having trouble finding information regarding what happens to a K atom when it forms a cation and when a F atom forms an anion??? I have looked everywhere but I can't find anything.

Answer:
Potassium atoms lose an electron to become a cation with a +1 charge.  They do this so they can have the electron configuration of the nearest noble gas, argon.  Likewise, fluorine gains an electron to form an anion with a -1 charge so it can have the electron configuration of the nearest noble gas, neon.  Since potassium has a +1 charge and fluorine has a -1 charge, they stick together to form potassium fluoride, KF.