The brown spots - look to me as if something has almost pierced the film. New film? Do they stay in the same formation but move around on the film?
Anything in the camera that could have done this?
Unlikely to be the lens. I presume you have checked it?
The creasing has to be some kind of winding problem. Is it 35mm film? Horizon? Are you able to wind with the back open to see how the film is transporting? And is the lens moving smoothly when you shoot?
Least of your worries at the moment, but it's overexposed
To give you a bit of encouragement here's some stuff shot with a Horizont by a friend of mine.
Plenty of distortion, but great cameras for the price
edit, when I think about it, it's probably a Noblex he uses, but they work on the same pricipal