I see you want to learn how to script NPCs. On your Hercules server folder, check out the documentaton for scripting. This will start you off so that your "little knowledge in this area" becomes bigger. You'll eventually become a great scripter!
The documentation for scripting is found in:
doc/script_commands.txt
I want to do X, where do I look for that?
Specifically for the things you want to learn, look for the following sections in the document:
Create an npc
Script loading structure, Script file format
which requires "xxx" zeny
Variables, Zeny
to register a "guild_name"
Variables
when the registration ends
*initnpctimer
if it was the guild name
Operators, conditional operators
teleport
*warp
the guild members
Arrays
Arrays may be a more difficult topic to learn on your own, but reading other people's scripts will help you understand how it works. You can ask questions.
If you get started on scripting it, I can give you some feedback on your code when I'm free.