How to socialize and meet people at 18?

I am an 18 yo guy, recently finished high-school and now I have a window of few months before I go to the military. During this time I want to meet new people, maybe go clubbing since I've never really partied at highschool or visited nightclubs. Maybe find a girl or smth. Just have some fun. What are the ways to meet people, socialize and find new friends?