Find yourself a hackerspace. They're collective-toolsheds of people around your community who find joy in making things, learning skills, and generally interested in helping teach others the skills that they know.

My local hackerspace, for example - has a 4 axis HAAS CNC, multiple metal lathes, TIG, MIG, Stick welders, leatherworking supplies, access to 3D printers, laser cutters, and lots of woodworking tools. We also had basically every console in existence and others bring in their game libraries for everyone to play.

They are also generally filled with college students that are burning the midnight oil quite regularly but may otherwise be somewhat solitary in their activities.

These places also will kind of locally crowd-fund new machines for people to use. They can vary wildly from space-to-space, some places being filled with old guys who are mostly into woodworking, or filled with young web-devs with no interest in welding, etc. If you are lucky enough to have multiple around your area, visit them all to see which one fits you best.

Also, membership usually includes 24/7 access to the space via controlled entry (membership keys, etc)

Dance clubs, comedy shows, open mic, tabletop gaming clubs.

LAN parties (showing my age).

It depends where you live, but my go-to was 24 hr cafes and other food places, but there are also other activities like late night fishing, long drives (or rides), night photography, etc

There isn’t much drinking at swingers clubs. At least not in the public areas.

24-hour coffee shops

24-hour diners, though they can get a little interesting at night. Do not underestimate a waffle House at 3:00 in the morning

24-hour libraries: these are rare

24-hour restaurants like burrito places.

Really depends what you want to do, do you want to just chill, or do you want to hang out with friends, or do you want to eat, there's a lot of options.

Crack houses are usually open 24/7 and while you can drink alcohol there, you're not expected to do so

Whataburger, Winco Foods, insomnia cookies, Denny's, and other diners come to mind. Since covid, hardly anything is open late anymore.

You might be able to find some other places local to you that we won't know aboht, if you satay up late and use the "open now" option on Google maps.

Book clubs. When I was driving a night taxi, the latest customers on workdays were book club people.

Music clubs too possibly, especially jazz.

Have you considered going to a bar and drinking whatever you want?

We have a sandwich shop that runs 24 hrs from Tuesday morning until Saturday night. I've picked up late night supper there and seen people playing cards, etc and just generally hanging out for long stretches.

When I was younger my buddies and I went to a 24 hr diner and played magic into the wee hrs, occasionally leaving only when the earliest breakfast crowd started to roll in.

Bowling Alleys (some), late night museum tours, late night roller skating.

They all have exposure to alcohol still. But can be enjoyed sober.

It really depends where you are - some places have a lively late night culture, others not so much.

All night diners, 24 hour fast food places are really the only alternatives here (though you could count movie theatres with late showings, I guess).

But (unless you have personal reasons for not being around alcohol and drinkers), you can totally go to a bar with a vibe you like and just hang out drinking soda. Bonus points if that bar has something cool available aside from just booze (barcades, live music venues, etc.).

If you're not looking to specifically be around people, you could also just check out some green space outdoors, but keep your wits about you and use your judgement - some places are lovely to chill at 3:00 am, some would be if it wasn't for the sketchy folks shooting up.

Hanging out at your friend's place with some board-games or movies. (cheaper too!)

Diners, if in the US is waffle house still a thing..?

Pool halls. I think some bowling venues. Less common, we have a cafe full of hundreds (maybe thousands) of board and card games. They’re only open until 11pm, but that’s still a place to socialize and meet up with people at night.

Several of my friends in my mid 20s didn't drink, so we usually would hang out at hookah bars. They are great, especially if they are allowed to serve food where you live. Most at least serve tea and other non-alcoholic beverages. I can give you a few pointers for first-timers if you are interested.

I used to belong to D&D groups that were open at a local comic store till like 4am.

We'd rent the space from the store at a good price, have pre-made characters for those that wanted to jump in.

If you don't have something like that local, I can imagine it wouldn't be too hard to start

Denny's.

I live in an area with a lot of muslim people, as they don't drink they often go to Shisha bars or Dessert bars. There's also a few tea house type places, fancy dark late night places that do posh teas.

You can check out https://soberbarsnearme.com

Diners.

Probably coffee shops

If it's to hang out with friends then those private karaoke rooms are a lot of fun

In Canada we call that Tim Hortons

Casinos

Dessert places. Ice cream, waffles, all that kind of thing. There are a few around here that are always busy 10-12pm.