Try out something like Timeleft (https://timeleft.com/). It's in most major cities now, and it will set you up with a dinner reservation for you and 5 strangers who are also looking to make friends.

I had a tough breakup a couple years ago and I know it would have been way tougher if I hadn't discovered Timeleft.

Even if you have enough friends already, you're at the age where it's probably difficult to get together regularly.

It's also good if you travel alone and want a night out in a city where you don't know anyone.