I'm sure you will not sound stupid or be made to feel that way.
In general, those who machine quilt have a wonderful understanding of all those aspects or variables that mytwopals mentioned.
Just about anything you imagine is possible.
The quilter will be able to suggest some ideas for you. The more experience they have, the more readily available the ideas.
If you don't know where you will be taking the quilt top, and you have several choices, go to each, and get their prices. They should have something printed up that is ready for you to walk away with. If you don't understand a term, ask for the definition then and there.
If you haven't seen any of their work, ask to see some! Who knows, they may have something similar to your quilt top.
If you do know where you will be taking the quilt top to be quilted, take it with you. Everybody will love looking at it, even if you don't go through with it.
If you come up with a rough idea of what you want, and they give you a pretty close estimate of the price, you can decide if you are ready to go through with it. If it's in your budget, you can most likely get your project on their waiting list or calendar. It's possible they will want you to make an appointment to discuss the details more thoroughly. There is no need to rush into such a decision. If they have already seen the top prior to the appointment, this will give them some time to brainstorm, too.
Oh, and it's possible the quilter will have some books of quilting patterns, to help you decide how to do each part, particularly the borders.
Good luck!