attacks – Attacking/Hacking a Server

I’ve been reading some news about hacked school server and I was wondering, how to locate/find the server used by schools? Is it a web server? Can the attacker hacked a school web server and get all the information he wantsusing a method like SQLi or something? Or is it another server?

One of them used LOIC and he managed to take down the network in the whole area(SYN Flood Attack), how did he find the server’s IP? And also how to hack a remote server and again, how to locate them? Like when the Chinese & Russian hacked the server used by the US governments and when the US accuses China of hacking Microsoft server. What server did they attacked/targeted? And how to find those server?

I never really practice to hack a server before so I don’t really have an idea for this one.