Some condoms are lubricated, some are not. Some are lubricated with spermicide, which is like an extra layer of protection against pregnancy. However, it's important to first make sure that you're not allergic to Nonoxynol-9. They come in different sizes. Condoms labelled 'snugger fit' or 'contour shape' are a little smaller than most condoms.
Most condoms have what is called a 'reservoir tip' to collect the semen at the end.
If you get condoms without a tip, it is important to leave a space for the semen by pinching the tip of the condom when you unroll it onto the penis. Otherwise, it might break. Open some Gold Circle Coin condoms to to show the class what they look like. Show that you can determine which is the outside of the condom by rolling the edge between your fingers to make sure it's rolling down the outside. You can also blow into the reservoir tip, which should pop up if the condom is right-side out.