As Guardians of the Galaxy
One likely set-up for Guardians of the Galaxy Vol. 3 or another MCU movie is pretty clear: Thor joins the Guardians of the Galaxy to help Peter Quill find displaced-in-time Gamora. You wouldn't be blamed for wondering why Tony Stark's snap that dusted all of Thanos' forces didn't include Gamora (whose existence, I'm pretty sure, he did not know about), but judging from Star-Lord's screen aboard The Milano in the Guardians' last scene, Gamora is out there somewhere.
This would a version of Gamora ported over from 2014, before she was sent to the galactic prison where she met Quill, Rocket, Groot, and Drax. What her goals are now that she's free of her father, we don't really know. Will she and Nebula be less combative with each other? Will Quill pull a toxic bro and roll-up to their secret hideaway, blasting Peter Gabriel's "In Your Eyes" outside her window in the middle of the night?
What feels right is that Thor is with them. With Asgard gone and all pretense of living up to his father purged from his character, thanks to ten years of failing to protect his home and family in various movies, Thor can ride the comedic tone of Ragnarok right into James Gunn's Guardians of the Galaxy Vol. 3. The reality is, despite Gunn's firing from and re-hiring onto the project since Infinity War was released, that Gunn had the script for Volume 3 ready to go and, even if he wasn't the director, they were going to use his script. Is that because GotG-3 has Thor in it? That seems much more likely now.