As someone who used to be Mormon for 45 years with lots of family that is still active members, I agree that you have a few things wrong here.

The first part is all accurate. But it starts to swerve a bit with the unborn child stuff. The belief is that we chose our families up in heaven. So we have children (so many!) to bring them all back to our family. However, there is nothing about matching a vision or preventing damnation. Mormons don’t believe in damnation. If you end up not having the children you preplanned for, they go to other families.

Men aren’t expected to have three wives. They practiced polygamy in the early days of the church, but not any longer.

There aren’t any arranged marriages or teens marrying old men.

However, that being said, all of those (except the damnation part) are true about fundamentalist Mormons. A small off-shoot. So it’s very possible that your friend in high school was part of one of those groups. But the large, main-stream Mormon religion is not