To get this trophy, you'll need to be partnered with 10+ unique travelers. While online, you should meet players rather quickly once starting a chapter. Once you've met the person, you can simply return to the chapter select and start a new chapter.
Alternatively, it seems that it may be possible to accrue partners while AFK, but I can't be sure.
Regardless, I would leave this as one of the last trophies since it's relatively easy to clean up, and other trophies require you to do specific things with companions. I would recommend attempting to get the trophies in this order:
The Companion trophy in Journey worth 60 pointsFinish the game with the same partner for the majority of the journey and return to the beginning. The Reflection trophy in Journey worth 25 pointsSit and meditate with another player for more than 20 seconds. and then finally this one. The reason for this is that you could accidentally unlock this trophy while going for either of the other two, and you might find a partner willing to meditate with you while completing the Companion trophy.