Hey there!
The levelcap on this server is 104 atm and most of the interesting dungeons are settled in that levelarea.
You should be able to see ppl in global chat looking for partys for Hall of Survivors HM (hos), tikal, inferno or gorge, which are starting at lv100. Here the game becomes way more populated.
Lower instances are rarely run, especially outside of guildruns, because all you need from them on this server are a few items for ISS.
I don't know which server you have played on before, but here certainly the playerbase does not support high activity in all the zones and dungeons of all levels, there are simply too many of them. So while leveling up, you might feel a little lonely. 
Cheers!
Most stuff u can ask in Forum. And there are more than the buy option to earn dias 
Hang out at Lost Island of Atlantis. It will give you a feel of the players population. Its the place to be to check out uber gear, etc.
Arcadia is more populated than any other server of this game.
The past days we are reaching records of online players.
It's cleary visible in chat activity & amount of items listed on AH.
The best way to get touch with other players is to ask about help / group on world chat.
I would suggest you to find a guild, so you can get help with your adventures on Arcadia.
If you played this game before, you should definitly check section for returning players:
https://chroniclesofarcadia.com/game-features/#for-returning-players
