Making friends as an adult is tough. When you're in college, you're in an environment that lends itself to connections. It's easier to meet people your age who share your interests. As an adult working full-time, I've had to make more of a concerted effort to connect with people. I have made friends at work, but it is different to meet people completely outside of any context you have like work or class.
I've mingled in some social meetup groups in my community recently and have made some awesome friends in the process. When we hang out, we typically have game nights where we play different card or board games together as a social activity for our small group. It's been a fun way to help get to know each other and just have fun outside our normal routines. While I was not one to play a lot when I was younger, board games have helped me solidify my first adult friendships, and I'm eternally grateful for that.
Some of the games that my friends and I play have been Cards Against Humanity (a common favorite), We Didn't Playtest This At All, Geek Battle, Man Bites Dog, and various others as well as just other random card games that some of us know of that we use a regular deck of playing cards for. It's been a lot of fun to discover new games like these since board games are experiencing a bit of a Renaissance now it feels like. Games like these just help us put down our phones and interact with each other through a simple and fun activity. Some of the games are mindless fun, others are competition based. A bit of friendly competition though is never a bad thing!
I highly recommend exploring this world of board games with your friends, if they're old or new, you can find a fun game to engage with. There are so many different types now that you can definitely find something you'll enjoy.