"Little" guy,
I feel sorry cuz no one's replied to your post so I'll do it, though for future reference, click on that blue button up top that says "search" and you should find some info on your questions.
First off, if you're 14 yrs old, 5'10" & 186 lbs why in the HELL do you need to bulk up? Is that 186 lean lbs or are you chunky? Standing 5'10" & 186 lbs @ 14 yrs old, you should be towering over other guys your age and probably run them over like a Mac truck.
If you're not lean, then loose the chub first through cardio & a clean diet and hit the weights hard. If you're already lean, hold off on the creatine till you hit HS bro cuz it doesn't sound like you're in much need.