You have three holes down there.
The first one is called the urethra. You couldn't fit a p***s in there if you tried. It's just a tiny hole that pee comes out of.
The next hole is the v****a. That's the most common place to put a p***s, fingers, or sex toys. Size is deceiving with this hole. A lot of people think the v****a is a big gaping hole, but it's not. It's more like a sock. It's sort of collapsed when nothing is in it. If a woman is dry, nervous, or not in the mood, the v****a can feel really small. But that same v****a can feel rather loose when the woman is lubricated, comfortable, and in the mood.
The next hole is called the a**s. That's where you poop from. You can put a p***s, fingers, or sex toys there too if you want.
Feel free to grab a mirror and inspect yourself. You can use your fingers to open your labia and explore your v****a if you want. Just make sure you never put anything in your a**s then in your v****a without washing it since there is bacteria in the a**s that are not good for your v****a.
Here's an article and diagram that might help you out:
http://www.scarleteen.com/article/body/anatomy_pink_parts_female_sexual_anatomy