First of all, the scrolling marquee makes it harder for people to read your question. Don't do that next time please.
Also, it's called a Guild not a clan. To leave, hit ALT+G (Brings up the guild menu). Go to the tab where you can view members' names and levels. Scroll down to your name, right click, and Leave.
There! You're guildless now.
To make a guild, get an "Emperium". That's an item which costs averagely about 100k each. Once you have that, type:
/guild "Your guild name here"
