advice before I meet with a personal trainer

[BigCummins]

Machines are usually reserved for the lazy, ignorant, or injured.

There is nothing "advanced" about free weights. They are just the simplest most effective modes of working your muscles when compared to gimmicky hi-tech looking machines. Machines just try to mimic the natural range of motion your going through when using freeweights. I find them to be quite inhibiting of my movement depending on the excercise being done.

It is a good idea if your new to learn proper form for the major lifts like wolfram mentioned, but this should be accomplished in the first couple sessions and then you can cut your trainer loose.