Something just doesn't seem right here. After central orientation, you should be paired with (ideally one for consistency sake) an experienced nurse for a few months. I am glad that the other nurse refused to accept that type of assignment as well.
As a licensed professional, you are expected to work up to your license. So even if you are doing vital signs and taking people to the bathroom, you are still expected to assess and react as an RN would. But without the proper training, how can you be expected to do that?
You need to talk to your NM, even as a GN you should have been receiving training as an RN. As a GN, I checked and hung blood, gave chemo, IV push medications, performed assessments and did my own charting. I had a preceptor who kept up with what I was doing, and did not have an additional assignment. After a while, she brought a book to work! But that is what was supposed to happen, so the day that I was on my own for the first time, I was ready for it.
Good luck, and start looking around to see what your options are!