Here is how you can make money as a security guard:
1. Find a large business park.
2. Commit lots of crimes such as vandalism, arson, and dropping cats on people's heads from above.*
3. Get a business card that says "I am an excellent security guard and am extremely proficient in apprehending people who commit vandalism, arson, and who drop cats on other people."
5. Wait around for them to hire you as a security guard.
6. In the meantime, continue committing crimes
7. If they do not offer to pay you enough, just say no, and then go commit more crimes. Soon they will offer more.
*I don't know if this is an actual crime or not, but it should be. There is no real defense if someone drops a cat on your head, so if you work at a business park, I recommend wearing a hockey mask at all times. This causes the cat to bounce off without clawing out your eyes and provides the added benefit of looking scary.