Board game or DnD club! I've met so many cool people at these things and it's a fun hobby to boot! :)

Are you into bars at all? Finding a bar that already had regulars who are fun group is a pleasant way to make friends imo and you’ll meet people naturally once you know some people. All you have to do is scope out which one feels comfortable and visit at the same time each week. Obviously watch out for raging alcoholics, but lots of folks are healthy(ish) and just there for companionship.

Meetup.com has events for a ton of different interests, I've found them to be quite diverse in age but some events are also focused for certain age ranges, so you might have some luck there!

Do they have to be in person?

This is pretty niche, but I'm in a casual curling league and nearly everyone is over 40. Everyone there is super welcoming and friendly.

I have a strategy where i'll get'em really hot by showing off all my 99s, but it's getting to that step that's been the hard part.