Double Retired provides some good advice. A quick search on the internet provides:
Join a group or club. Find a local group where people with interests like yours meet regularly. Try a book club, religious group, parent meetup, music group, or biking group. “The key is to fish in the right pond,” Grossman says.
Take a class. Sign up for a class at your local college, senior center, or gym. Learn Italian, dancing, or a new card game. When the topic interests you, you’re likely to find people who share your passion.
Look locally. You may be surprised by how many events are happening right in your community. Look in your local newspaper or community bulletin boards. Go online for neighborhood listings. Search the name of your city plus the words “social network” or “meetups.”
Volunteer. People who work together often form strong connections. Meet people by volunteering with a community center, charitable group, hospital, museum, or place of worship.
Join a social circle. One of the easiest ways to meet people is to surround yourself with people who have large friend groups of their own, O’Brien says. “You may already have people in your life who have a lot of friends,” she says. Join them when they invite you out. Ask for introductions. Take the first step and start a conversation with someone new.