Pre assembly sliding nuts

Either because I’m a dunce or because the instructions/photos are unclear I’m having trouble figuring out which side of the spindle carriage the two sliding nuts used for belt tightening are supposed to be on.

Also, in the early stages of assembly a plastic L piece that’s part of the drag chain system (I guess) is installed on one of the Y plates. I did that but it doesn’t really say which side of the machine that should end up on. Any guidance would be greatly appreciated.

Please disregard the above post. It’s true the pics and descriptions are unclear, but my wife clarified for me that in fact I’m a dunce. This is now resolved