How to shoot with my nikon d3200 in abandon buildings?

I'm going to an abandon insane aslyum today, and an abandon subway with a lot of graffiti down there! What settings on my Nikon D3200 should I use? Apeture/f stop/shutter speed/ISO? What setting?

That's why you have an exposure meter.

Without actually being there, nobody can tell you precisely, but I'd suggest keeping your ISO high enough that you can use a medium aperture without experiencing camera shake - but you'll have to find out for yourself.

You ask "Apeture/f stop/shutter speed/ISO? What setting?"
The ones that give the correct exposure, depth of field, noise level and motion freezing for each individual shot.
That is why you have a fully adjustable camera - so you can adjust it to the perfect settings for each photo. There's no "one-size-fits-all" - if there were then who would need pro photographers? Who would need an adjustable camera?

Do you have a good tripod? If not, get one. It will be a must-have.

The reason is that you'll work a lot in low light situations in which you also will want deep depth of field. While using short focal lengths (zooming out) helps with the latter, being able to step down the aperture a bit for even more DoF will be desireable often. Also, even wide open it likely won't be bright enough indoors to shoot without raised ISO.

With a tripod you can counteract this with long shutter speeds, allowing you to keep the ISO down and also using a somewhat closed down aperture (f/8 to f/13) for the depth of field.

Reading some tutorials about long exposure photography also would be a good idea. There are subtle techniques such as using remote shutter releases or the self timer to further reduce camera shake that improve the results.

Assuming you don't have a tripod or a light meter or a dfetachable flash/strobe? And that you are relatively a dslr newbie? You might be able to get decent shots set on auto - hey just experiment, look at what results you get - and most of all HAVE FUN!

For a Quick fix, leave on auto. Sounds like excellent places to get camera stolen.
After quick fix on auto, go home and read manual. Buy a book on Basics of Photography. One doesn't buy a DSLR and then ask what aperture, shutter speed, ISO setting.
Secondary quick fix: Set ISO on Auto, set shutter speed about 1/60 second. In aperture/shutter priority mode aperture will set itself.
A tripod would help although inconvenient. You might go down to 1/30 sec on shutter speed, hand held.

How? You take three 250-pound bodyguards armed to the teeth with you.