To meet gay people almost every city has a club, discotheque or bar where gays hang out. You need to search in google for your local listing of gay places of interest. You will not find a gay, say, at the mall or at work; because most of them hide their true self in social environments. I have seen many in some outdoor places I have been, who are not afraid of showing who they are, but those are very scarce.
Wish you luck either way!
The answer to this question depends on a number of variables and your particular reasons for wanting to meet gay people.
If you are gay and want to meet other gay people because you feel isolated and just want to learn more about what it means to be gay, then your best bet is to locate gay organizations. In larger cities, there are usually a number of such organizations, and a Google search using your hometown and the word "gay" might be helpful. If you live in a smaller community that does not have any gay organizations, you may wish to search using the name of a larger city near where you live.
If you have recently graduated from high school or are college age, you may also wish to check out any local colleges and universities to see if they have gay student groups. Even if you don't go to the college, many such groups are welcoming towards people of that age, since they are very aware of the difficulties young gay people sometimes face.
Youth Resource ( http://www.youthresource.com/ ) has a searchable database of gay youth groups throughout the United States.