How to start a Network Security Business as a Certified Network Security Specialist?

Hello! Can anyone please help me with this question? Thanks! I am getting certified in Network Security from my school and should be finished within a month. I plan to start a Network Security Agency or Consultant Group. How would I go about this? Is there a large number of businesses willing to pay for an outsider to mess with their Networks Security? And what type of businesses should I start to market too? I have done searches on this through numerous search Engines, but nothing has come up. I appreciate your responses. Thank You all ahead of time!