I've done pedi private duty before, and we oriented until the nurse was comfortable with the vent.
Most nurses who came to pedi private duty were not familiar with the vents and we oriented them until they were.
How long is your orientation to the patient? Were you allowed to attend a ventilator class? (Ours was taught by an RT that worked with the supply company). If not, ask them to attend one.
As for programming, all you do is turn it on and off

Numbers are pre-set, and are just double checked against the order.
Also, remember there should be a supervisor on call 24/7 (been there!) And as much as they may not like being woken up, the patient comes first. Just make sure you are properly oriented to it, and they give you as much time as you need to learn the vent.
And last but not least, good luck on your new job!!
-Meghan