Trying menstrual cups

So I’m trying to switch from tampons to cups but I can’t get the cup in. I’ve tried folding it different ways and I’ve tried different positions and I still can’t get it in. I use a regular size tampon and I’m trying to use a small cup, do you guys have any tips please? How long did it take you to get it in? Does it matter if you’ve had sex or not? Is it possible that I’m too small for the cup and that’s why it won’t go in? I’d really appreciate some help with this.