As with most things, the hardest part is the first step: you have to find a community to join. It can be anything, but senior centers are greater resources for older people that they unfortunately don’t take enough advantage of. My parents found a seniors’ program at a local college and started taking classes with people their age, which created an entirely new friend group for them. You just have to find a group of people doing something you enjoy and the relationships will likely form without much effort after that, provided you don’t have crippling social anxiety or something else that makes social interaction difficult. Point is, once you get the ball rolling, momentum takes over; the hardest part is getting it (i.e. yourself) moving.