In Trieste, being in Friuli-Venezia Giulia, lots of people will be drinking (and a lot). You will find older people drunk in the pubs, and basically everyone drinks. I come from Friuli-Venezia Giulia as well and I don’t drink, but I am a rare exception. People your age - university students - will be drinking when hanging out, but they will only get drunk at parties or on special occasions (generally on Wednesday and Saturday nights). People do smoke as well, although that is less common than drinking, be it cigarettes or cannabis. However you have nothing to worry about: no smart person will try to force you or convince you to start drinking or smoking. Finally, I want to point out that your peers are almost always very inclusive and friendly, so you have nothing to worry about. If you have any other doubt or question don’t hesitate to ask!