Find an activity you like. Preferably one involving members of the target gender.
Hiking, biking, rollerblading, ski, outdoors clubs. Book discussions, volunteer activities (museums, libraries, boys/girls clubs, scouts, hospitals, soup kitchens), Socrates’s cafes. Religious groups. Dance - take lessons, you meet lots of opposite gender people (how my wife & I met). If your school has an alumni association, hook up with them and find out if there are activities in your area. If not, start one! Do anything, as long as it’s fun and you meet people.