My advice would be, try not to do anything too difficult at first. Just enjoy the dream and explore what you CAN see. Try floating\flying and maybe try to go through a window. This may open up an outside dreamscape that will be more fun.

Blindness tends to happen when you're trying for something too elaborate. If your brain cannot quite generate the images, you just go blind. Often followed by waking up. Too much exertion can also wake you up.

Just try and enjoy what you can see until you get more experience.