Hey PTLRM! I know the feeling. Honestly, you're a new grad...don't sweat this feeling. It's the last lovely feeling of student anxiety, and it might last for a year or two.
I never expected the new grads to know everything when I was working in acute! I always appreciated people asking questions. As long as you're safe and don't do anything that could harm a patient, you're just where the rest of us where as new grads. Exceptions, of course, would be new grad PTs who had really strong acute clinicals. I had no acute clinicals, so I felt like a total booger eatin' ***** when I first started 🙂
As far as safety goes, don't worry about productivity, looking competant, or pleasing nurses/doctors. Worry about your patients right now. Take the time to check H&H and blood pressure before you get patients up. Watch your patients' heart rates when you ambulate them. Ask nurses if there's any reason not to see patients. Always get help for patients that aren't straightforward "walkie talkies." PM me if you ever have questions!!!