Have to agree that Meetup.org is a great place to start. It is NOT a dating site. Just like minded people with similar interests getting together with other nice people doing things they enjoy. I joined a walking one. It's been terrific. In 3 meet-ups, there has been 2 or 3 new people each time.
Reach out to friends, both old and new. If you are faith-minded, dive into activities at your place of worship. If you don't exercise, start NOW. Gyms are very social places, and it does wonderful things to the mind and soul, too. The most important thing is to not sit at home alone for long periods. This is the time we start obsessing over things, and that is not productive at all.