I really don't understand your problem but the first thing you do (if your talking about the black plastic clamp is to removed the tightening knob from the inboard hole (closet to the fence and put it in the out board hole, (farthest from the fence) there are only 2 holes. then after you got the fence squared with the rail GENTLY slide the clamp up into the groove on the fence and tighten.
Also though you didn't mention this issue yet (not getting square cuts which is very common to new users) you need a known good square square to set up the rail/fence to a true 90. I recommend either the woodpecker 1281 or the ply square by Anderson Plywood.
There are other squares and methods (dogs etc) but these are the 2 I use.
Now the video. There are plenty of videos on FestoolTV that can help you with just about any situation you may run into.
Hope this helps