How to disconnect display from MacBook Pro?

I have just bought a MacBookPro and a second-hand 24" cinema display. I've connect the two and everything is working fine. But I now want to disconnect the MacBook and use it in a different room. How do I do this? I'm using the MacBook in clamshell or closed mode.

Do I simply unplug the connecting cables? But then how do I turn the cinema display off? There is no on/off button. Do I have to turn it off at the wall, or does it use no power when not connected to a computer?

Before unplugging the cables do I have to turn the MacBook off?

I'm using the MacBook in clamshell or closed mode. After turning it off, how do I turn it on (when in clamshell mode)? I presume I have to open it, to turn it on?

Thank you