Should I turn off my MacBook Pro?

So I'm new to this whole Mac thing. Last time I used a Mac was back in the 6th grade and I'm now a sophomore in college. I recently bought a 13 inch MacBook Pro for school and I don't know if I should leave it in sleep mode or turn it off completely. Right now I'm at home and I got a desktop pc as my main computer so I don't really touch my MacBook at all. I won't be back in school for about another 3 weeks. Should I turn off my Mac or should I just leave it in sleep mode and charge it every few days? Thanks in advance.

Safest bet is turned off with a 50% charge. Too low charge can cause discharge and too high can result in capacity loss.

MacBook.... never turned it off in almost three yrs other than restarts for updates or OnyX maintenance. Ran like a charm and never had problems.
MacBook Pro, same deal.
You can leave it off or in sleep plugged in or not, no harm is going to come of it, but if you're not going to touch it, you may as well turn it off.

I agree. I never turn my mbp off except for the restarts and when I'm traveling. I was told to shut it down during transport.

I never turn mine off either, but I also never go 3 weeks without using it. If I knew I was going to be away from it for a month, I would turn it off. The suggestion I gave is what Apple recommends, so that is what I would go with.