If you have money to spend here are some ideas:
- multicopters flight in field of vision or FPV
- RC cars, there may be some RC race tracks around big cities
- if you have some sea or lake nearby, windsurfing might be good idea
- photography
More cheap ones
- find some hackerspace or maker groups, they usually understand that someone needs less social interaction, and you can learn to build stuff
- bird watching
- ingress mobile game (or any other made by niantic)
Idgaf - i don't give a fuck, I'm me