You need hamachi, (https://secure.logmein.com/welcome/access/hamachi/1/?wt.srch=1&utpk=hamachi&destination=/welcome/access/hamachi/1/&originid=56890&ef_id=HcdOOIty@wYAAM7J:20110802234242:s) then after you get that hit host and play, choose character, make a map or use one of your own, let people join your hamachi and tell them to join you.
Just Google Terraria servers and copy the ip address into the multiplayer slot on terraria.
Unknown
Is the server up? or is the owner asleep or somewere.
A public server is that you have to buy it but a dedicated server to make public means you have to forward the ports of your router.
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.
To make your Minecraft server open for the public, make sure that your white-list is off. Then you will want to go to minecraftservers.org , and register for an account to submit your server IP.
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.
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.
There is no such item as Pewpew in Terraria.
There are several common reasons you might be unable to connect to a Terraria server. First, ensure that you have the correct IP address and port number, and check if the server is online and not full. Additionally, verify that your firewall or antivirus software isn't blocking the connection. Lastly, ensure you're using the same version of the game as the server, as version mismatches can prevent a successful connection.
Your own server, no unless you make other people pay to get on. Public Servers, depends on the person running the server.
At least phaseblades and the jungle armor breastplate, but for more info go to terraria wikia