Unknown
Is the server up? or is the owner asleep or somewere.
There are no main server on terraria so I would suggest google searching "terraria servers" and see what comes up. I have done this and been on multiplayer.
About $15
Sorry but is not possible to get free Hearts Shards in Terraria. Unless someone on a server with you is nice enough to drop a Heart Shard for your liking.
sad-da-sda-d-a-
The server version should be in the title bar. The client version is in the bottom left corner of the main menu. If they're not the same then it won't work.
Anyone can give anything on a server and you would get to keep it, just begging people for it is hard, but the obsidian skull is not hard to make. Only 30 obsidian.
Terraria happened in 2011.
Search "Terraria invedit" on youtube.
If you have Terraria on Steam it updates itself once an update is available.
Only a GM/Gms of the server can do that.