Learn one or more things about Penetration testing.
First thing what I learned today about the topic is the difference according to vulnerability scanning. During scanning you identify and prioritise possible vulnerabilities, but during penetration testing you actively explore those vulnerabilities with the aim to break in.
Second, very important thing what I learned: in Germany all penetration testing without permission of an owner is illegal. So if you will scan somebodies system in the Germany, try to use the vulnerability and report it to the owner with hope to get a reward, you may land in the jail.