I moved from Italy to the US 8y ago and my way to stay in touch with my friends has been to do side projects left and right. My suggestion is to brainstorm projects with your friends:
1. You want to find a project that you like, of course, but the other person should also be pretty sold/invested in the idea.
2. Brainstorm 1 to 1, you can always involve other people later.
3. When you find 1 person/1 project, jump right into it or enthusiasm will fade quickly.
4. When you start something, tell everybody and try to attract other people.
It's generally hard, the main issue is timing. You now are free/motivated but many or your friends are prob not. But if you persist, sooner or later you'll find the perfect match.
Like I said I did many side projects in the past years, some for a weekend or two, some for a few months, some with 1 person and one even with a "team of 5". Finally, the stars aligned and with one of my friends decided to go full time. Good luck!