Grad Application: Does a bad exchange semester matter?
It does totally depend on the inherent nature of your overall program. Exchanges are often considered within the main path of the program. If so, you have no way to camouflage that poor performance. But if you can, legally and reasonably, skip that part, such that your program would not be under effect of any gap, you better leave it and try to augment the rest of your academic trace.

You need to prepare official certified copy from the university, which did issue that transcript. Take that copies into account for the apply.

Best