Talk about drinking and driving. Shy, insecure teens can be encouraged to join clubs or activity groups where making friends is easier. You can get information for yourself. If you suspect drug use, offer support for wise choices along with disapproval of the unwise ones. Teen love is serious.
Breakups are devastating.
Your sympathy can help diffuse anger and depression. Plenty of love at home can make it less urgent to find love through sexual encounters. You can explain how fear of pregnancy and disease changes relationships. Both of you may be embarrassed at first if you're too direct. But related issues can open the door.