Back in college, I would go to house parties and bars and do everything that everyone else was doing; the only difference is that I would have a Coke in my hand instead of a Rum & Coke.
That was (mostly) fine for me, because I never felt the temptation to drink, and the fun I derived was from the social enjoyment, not from what I was drinking.
But I've had friends who struggled with alcohol addiction, and for them, it was much more beneficial to change their scenery and get away from the parties and bars and clubs where drinking was a big part of the experience. Sometimes you also need to distance yourself from friends where your friendship really only works because you both like drinking together.
Stuff that seemed to work:
* Some people found that they could replace the fun from alcohol with adrenaline rushes, so they did things like power sports, skydiving, roller coasters, etc. But of course, those tend to be expensive ways of having fun.
* Others cultivated hobbies and then looked for social experiences that aligned with those hobbies. One guy loved pinball so he joined a pinball club in his city. Another joined an adult sports league.
* One guy I know, who also struggled with drug addiction, decided go in a different direction. He felt like he didn't want to replace one addiction with another, so instead he was determined to rewire his brain so he wasn't constantly chasing the next high. He did meditation, mindfulness, self-help exercises, therapy, etc.