The pelvic floor is an anatomic waste basket term that usually refers to the inferior/ interior pelvic bones, the muscles of the base of the pelvis, and some non-muscular connective tissue, like the perineum and the base of the peritoneum (the lining of the abdominal cavity). Other than kegel exercises, I don’t much know what the pelvic floor has to do with PE, unless you consider the root attachments of the corpora cavernosa at the pelvic bones.
With that in mind, I don’t know what damaging the pelvic floor means in terms of PE injury. Please explain.
The most common PE injuries I can think of are superficial, related to the skin or superficial veins just under the skin. More serious injuries are more rare. Some are acute, like injuring the tunica during erect or semi-erect exercises (which are an advanced technique) or damaging the suspensory ligament, and others are more subtle and possibly cumulative, like causing venous insufficiency from repetitive high pressure pumping or possibly jelqing. But these are more rare.
If you have a specific concern then it might make sense to be specific in asking a question about it. Somebody on the board is likely to be able to offer something useful.
If you’re worried about general risk, then just take it easy and slowly build up your intensity along with your confidence.