I feel like I'm in the same boat. I got a holiday work visa and lived in Australia when I was 29, and New Zealand until I was 32. For the past decade, I've never lived in the same city for more than three years.
Meetup.com, swing dancing, reddit meetups, board game nights, spoken word poetry, comedy open mics, theater, contra dancing are just a couple of the things I try to get involved in (I get burnt out on a few and rotate hobbies; dropping in and out of scenes).
It usually takes me about a year to a year and a half to make a solid group of friends in a city, but the friends I've made, I've kept in touch with all around the world. Going back to my home town was amazing too, even though so many people I knew had moved on. I wrote some blog posts about being nomadic:
Meetup.com, swing dancing, reddit meetups, board game nights, spoken word poetry, comedy open mics, theater, contra dancing are just a couple of the things I try to get involved in (I get burnt out on a few and rotate hobbies; dropping in and out of scenes).
It usually takes me about a year to a year and a half to make a solid group of friends in a city, but the friends I've made, I've kept in touch with all around the world. Going back to my home town was amazing too, even though so many people I knew had moved on. I wrote some blog posts about being nomadic:
https://khanism.org/perspective/a-tale-of-two-journeys/
https://khanism.org/perspective/minimalism/