Suggestions/Tips Needed

Hello everyone, Had the sleeve on 5/11/15, I walk 4 times a week for 45 minutes. Tonight I start with a trainer, she is going to set me up to do the weight machine circuit.  I'm a little nervous and don't know what to expect.  My muscle tone is terrible and I have very little strength.  What has been your experience with weight circuit machines, what can I expect?  Thank you and have a great day. 

I started with a personal trainer about 2 months ago and my first meeting was a fitness test to figure out where I was at.  The trainer is great and it's been a good experience.  I also didn't know what to expect, but I was totally honest with him about where I was at.