Everything from the universe is created from the mind. Sleep Paralysis is the phenomenon of awaking or switching in to sleep. It can't harm you since it's all mental, but if you attempt with the right mind set, I don't believe you will see anything out of the ordinary.

Dream checks are only necessary if you believe you are in the dream state. Some dream checks include, looking in the mirror, flipping a light switch, looking at your hands, etc. There are endless more checks.