Preparing for a night of drinking and the day after

Hello! I just turned 21 (weight about 190 lbs) and this Friday night I was invited to drink with friends who are way older than me for the first time. I just don’t want to get terribly hungover on Saturday afternoon to the point that I can’t drive home (I’m planning to stay at their place for at least 12 hours after). What should I do before drinking and if I did have a bad hangover should I just stay extra hours to let it go away?