I'm a Registered Respiratory Therapist. One piece of advice that I can give you is to not be afraid to rely on the respiratory therapist assigned to your unit. If you feel like you're in over your head, or the patient is going down the tubes, or even if you just want respiratory to swing by and give you a second opinion on something, don't hesitate to ask us. At my hospital, so many nurses (we hire a lot of new grads) are afraid to ask for help with a patient until it becomes a Rapid Response or a Code situation. Please, please page us, call us, grab us, yell for us, etc if you need help! This is our specialty! I would much rather help you out early on in a situation when things are not critical rather than hours and hours later when the patient is in distress. Most RT's like to be proactive.
That said, like any new job, just take your time with things. If you're not comfortable performing a task by yourself, let someone know. If you're unsure of something, ask for advice. When I first started working, I was terrified of alarming vents, trach patients, very sick kids, c-sections, etc. Basically I was scared of everything! I relied heavily on my coworkers for moral support and over a year later I am an old pro (almost! haha) that rarely stresses about anything.
Just keep in mind that it's in your coworkers best interests to help train you well. In the long run you will be more of an asset and less of a burden. And also remember that every expert was a beginner at one time as well. Don't pick up too many extra shifts, you'll risk burning out early on. On your days off, don't think too much about work, but also don't be afraid to study up on drugs and concepts that you don't understand. Google, your school textbooks, and youtube should be your best friends!
Good luck and congratulations on your job!!