A personal trainer can be a great teacher and resource if you want to reach your goals faster and without injury.
Ideally a new member should come into a gym and, if they have any doubts on how to work the equipment, have a personal trainer provided to them for one orientation session where they can have all of their questions answered. They should leave that session with a basic understanding of how equipment for major muscle groups work and, if they ask, should have the information such as sets, reps and weight for each machine used, written down for them. That is where an orientation begins and ends. If a trainer is ignoring your request to learn the machines you ask about, make very clear that you will end the session and you will ask the PT manager for another trainer to do the orientation because your needs were not met during this one. On the other hand, if you feel confident about your knowledge of machines and would like to spend your free hour with your trainer learning new things, let them know this during your phone conversation and most trainers are happy to oblige.