Well, Amber, that is a fairly complex subject, isn’t it?
Books have been written about it.

There is little doubt that they learn from TV and movies and music.
They learn that sex is good.
I think that is correct, I think a large part of the problem with teen sexuality is that we as adults attach a stigma to it, usually derived from Christian thought, that makes it a “guilty” pleasure.
So, we should be open to our children’s questions and teach them about safe sex and safety, as in safe sex and safe associations.
I’m thinking you are Jewish, if so, in our beliefs I don’t recall hearing any negative comments about sexuality or guilt associations, so that is less of a problem for us than Christians.

From Movies, TV and music they learn about violence as well.
My thoughts and goals with my children was to stress kindness.
I taught my kids about self-defense, but I stressed kindness in dealing with others and in their view of society.
And humility.
And service to others.
My adult children have turned out well, one is a social worker and the other is a nurse.

I hope I haven’t told you more than you wanted to hear.