I definitely recommend FB groups for activities you're interested in (my husband and I have made a couple friends through the kayaking and motorcycle groups we're in).

And, uh, if it's not overly dorky, I've legit made friends while traveling by playing Pokemon Go. It was a bit different before the pandemic, because everything social needed to happen relatively close to the gyms to battle and now Pokemon Go lets you do stuff from a distance. But if people are starting to congregate around the gyms again, it's a fun way to make a wide group of friends.