Clutch defective and no longer starts

Hello, my wife has just left. Clutch fluid has leaked out and there is no gear in it. At the same time, the car no longer starts. How can this be connected? I already read it, clutch encoder cylinders defective.. but why doesn’t it start? Where can i find the cylinder? Will also look for more posts, but if someone can tell me already fix wqs would be great. Thanks and beautiful We Uwe