Depends how you want to play. If you just want to chat, sit in town, people go by some will sit. If they're sitting they're usually willing to talk. But some people like to AFK there. Chatting here is like it always has been though, like the forums haven't really changed despite the addition of the game. Before it was added its not like the forums were active.
If you mean to play together more literally you can team up and travel around together, personally that drives me mad I prefer to head out alone.
The team up makes you travel together, but then you can't battle together right now. I don't know if that will change but right now only works to do certain things, or play certain games. Like only the party lead will be able to move map, if you get into battle you all do your own battles. And even if you try to leave the map or move on it will refresh you back into the map your team leader is on. So you have to wait and move together. During party events you team up and then play a game like the egg hunting at Easter or target shooting. Neither of those are up right now.
You can care for animals and farms together, and if you have a buddy crafts are way easier since you can pool together your resources and then handle different jobs. I don't think you can tell someone else's kogo to work. Maybe you can, I've never tried. You can complete their jobs for them though. Works like a multi player Harvest Moon or Rune Factory. I don't think other peoples relationships with Townspeople will effect yours opr vice versa so you can probably level up all your stuff and do whatever quests without any worry of negatively effecting anyone you want to play with. Besides maybe getting way ahead of them.
All said and done though US evening hours tends to be when you'll find people. If you in a time zone that sticks your afternoon/play time in the US morning/work/school hours it'll probably be hard to find anyone. But if you buddy up with someone in a different time zone you could also help each other out by helping their animals when the other is asleep.
There's silly stuff you can do with people too. Some people have gotten really good at making selfies together.
This thread usually runs things that have people gathering up, and you can grab nice items in the process. The last event just ended though.https://solia.online/forum/Solian+Commu ... ns/342810/