How to turn the flash off in different modes

athenab12

I'm a complete beginner with cameras, and I just got a Nikon D3200 for my birthday. I love it, but when shooting portrait, kids, big plan and nighttime shots, there's a flash. Don't get me wrong, the flash can help, but I really don't like it on my photos. I've read questions on this forum about the flash, but I just can't seem to find/get it.
So, how do I turn it off ? I would also like to know how to turn it back on, if I ever start to like it.

Thank you in advance!!