I don't know what your program uses to evaluate for clinical, and I don't know how your program determines the pass/fail aspect- but it sounds like the instructor basically gave you an "unsatisfactory" rating for your first day. The good news is, YOU CAN ONLY IMPROVE FROM HERE! In my opinion, if your instructor did not properly orient you to the unit you're having clinicals on (here are vitals machines, here is the nutrition room, here is where clean linens are kept, etc), they failed in one of their duties as well.
I think the most important thing for you to do now is practice managing those nerves. I was such a nervous heap on my first day of clinicals I tried to take a radial pulse ON THE ULNAR SIDE OF THE WRIST (**facepalm**). That being said, I finished that first round of clinicals with "exceeding expectations" as my final rating. I remembered I was there to learn- if your instructor is not willing to help, there is certainly another student or a nurse or a tech on the floor willing to lend a hand (especially for something as trivial as the location of a BP cuff). Nursing will be a stressful job (I'm only in my third semester where I'm taking care of three patients, not five or six and most days I feel drained)- your instructor may simply be trying to push you in order to encourage better coping skills. When in doubt, simply remember the patient takes priority; not paperwork, not charting, the patient and the patient's safety are number one. Take a few deep breaths, count backwards and forwards in your head, roll your shoulders a few times, find something that brings you inner calm and go from there. You'll get through this.