Please help. I am getting frustrated!!!

I am a new grad and still waiting on my test date for the N-Clex. I recently took a job at a facility on the sub-acute floor on the 3-11 shift and for the most part I really enjoy it. I was offered a job elsewhere on 7-3, however I declined that position because the DNS at this facility was very upfront with me and told me what she would expect from me as a nurse on this unit. I really liked what she stood for and what she wants out of her nurses. The problem is that I have been there for 1 month now and I feel like I am getting somewhat of a handle on things and want to be able to try things on my own. How else will I learn?This weekend was great I was able to take a med cart and have my own assignment. Tonight I get their and it was supposed to be the same thing however one of the other nurses who is also an LPN was having a major problem with it. She stated I am not responsible for her, and she is only supposed to be by herself if the RN is on the floor at all times. Well our RN supervisor floats throughout the house all the time on evenings, and this wasn't a problem over the weekend. If I was to screw up it wouldn't be her at risk and even though I am not yet licensed I can still be judicated for any wrong doing and the RN would ultimately be responsible. I also have no problem asking questions if I am unsure of something. I even have another nurse always check my injections because I don't feel comfortable with that yet. I just feel like when I do get my license I will be thrown to the floor and not feel confident. At least right now I am on orientation so their is always someone to go to if need be. I just feel like I take 5 steps forward and 10 steps back. I almost think I sould take that day job at least their will always be an RN on the floor and I could get started on my new career for real. Sorry for the long post. I hope someone can give me some advice.