in a pickle!!

ok so I put out my resume and applied to about 10-20 jobs a week. I finally got an interview at a place much closer than my current position for a little bit more pay. I was first told that I would interview in front of the two managers that were hiring and told to show up at this time on this day. I followed through on my end of the deal but only one manager was there. I seemed to get along with her very well. I received a phone call the next day saying my interview went very well but they thought I would be a better fit for the other manager and set up a time where I could meet with him. I was offered the job the day following that interview. I went in and did my paperwork. Then I went in for some computer training and was scolded about how I was not in dress code. I had never received a copy of the dress code. I wasn't wearing anything distasteful or offensive, just not business casual as I was going to be on the computer for less than an hour and not having contact with anyone but the HR lady. I then was asked if I could work a different shift than what I was offered at the time of the job offer. I was offered nights and now they want me on days which is what I prefer. Now in the midst of this mess I received two phone calls from hospitals wishing to interview me. One set up an interview and then JCAHO came and so they had to reschedule for in two weeks. Ok. Not a big problem. The other hospital set up a time with me that I accepted thinking I was going to be working nights but now am scheduled for training at the time of the interview. It is in front of 7 hiring managers. I currently have a job that I had as an LPN. I do not like it in any way. I also do not want to miss out on a possible hospital position and the one that conflicts with my training is the job I am more interested in. Do I call the interviewing hospital's HR and try to change my appointment time or do I call the job with the training?