You don't, but notch plans to add voice chat sometime soon.
If you mean you cant kill people than its because you have not enabled PVP you can do this by going into your minecraft sever folders and find the notpad file called "sever" and find PVP and change it to: PVP=true this should work, but if you are not dieing by spiders and zombies and stuff than i can not help you
Yes, Multiplayer comes with Minecraft on the PC.
You need an account to play minecraft multiplayer.
Sadly, no
First you start Minecraft, then you go on "multiplayer" and type in an ip !
Minecraft is recommended for ages 10 and up. It is rather 10+ by the ESRB for fantasy violence.
If u have online, then u should have multiplayer on minecraft
Yes, there is multiplayer in Minecraft.
Scottland
Port forward it.
43.34.43.12:25565