It is difficult to make new friends these days. Lots of people have held onto friends from school or university, but in the adult world, unless you are fortunate to meet people through work, then it's damn near impossible to meet people who will become real friends.
I am still in loose contact with a couple of people from school and university and some I've met through work and more recently a few I've met through the gym I work at, but I can only take them in small doses. People seem to be very self-centred these days and they tend only to make contact, when they want to talk about themselves.
Maybe taking up a hobby like an evening class or even a dance class. I've come across a few people who have met new people from Ceroc or Salsa classes, they always need male partners for female dancers.