Penny, allow the entire page to load and press control and f and do a search on vinyl. In the past, Jay and I and others in response to questions at different times have listed sites where you can download installation instructions from different manufacturers. I don't have time to search it myself.
As I recall, I believe you can install over stucco, per se. The real problem is having a solid wood surface (not foam) behind the stucco or even finding studs to nail into and having long enough nails to do all this. If you have a solid wood nailing surface behind the stucco and the stucco doesn't break away then it should work.
As I type and recall more, I believe the instructions said if there is not solid wood nailing surface then you have to nail 1by2 furring strips over and into each stud behind the stucco and apply the vinyl to the furring strips. I think that was the method to apply it on brick also.
Get the installations instructions for the vinyl you intend to buy and install and it should tell you and watch out for expert advice from the home cheapo stock boy/cash register checker/floor sweeper. I don't deal with stucco so I'm no expert on this. You need to install it according to the siding mfr's instructions if you want the warranty to apply. Good luck getting your exterior door and window frames to look right after adding another layer of siding.
If you really hate the stucco, start at an inconspicious spot in back and start removing it. It is basically masonry put on some chicken wire that was nailed to the siding. That will make your door and window frames match better. Find all the neighborhood vandals, give them a hammer, and let them start vandalizing your stucco. Lay a tarp down to catch it as it comes off.