Probably not but it's wise to set the display to sleep when it's not being used. Go to the Energy Saver settings in System Preferences. Also as new user I'd recommend navigating to http://www.apple.com/support/macbasics/ to learn how to use. Great reference material.
There is always a minor risk of screen burn, but this is easily avoided by using a screensaver without bright spaces, or letting the screen sleep without powering down the hard drive.
But just in case:
Apple say this about LCD screen burn in:
which includes suggestions for curing that effect.
How to fix screen burn and/or stuck pixels on an LCD monitor:
Your welcome, using a screen saver (again look in System Preferences) will be greatly beneficial or do what I do. I have my display set to sleep after 15 minutes of non use, this preserves the display and saves energy too. That way i can leave my computer on 24/7 without any issues. I have doing this for years with all of my Macs.