Personally I'd keep something basic along the following lines:
- small multitool w/o knife blade (not too many good options there but the LM Knifeless Fuse would be a decent pick)
- LED flashlight
- lighter (BIC, Zippo, whatever you like)
- cell phone
- some cash
- at least a couple of pens or pencils and a small notebook
- small bundle of paracord, twine or rope
- very basic first aid kit (adhesive bandages, painkillers etc.)
- maybe some spare batteries for your flashlight and any other items than run on batteries.

You could add some more stuff but it's good to keep it compact and maintain a low profile. If I were in your situation, my main priority would be a knifeless multitool. If you have any talent whatsoever for fixing things mechanical, you will appreciate having some tools at hand in a possible emergency.

I'm not sure if self-defense is a major concern. If yes, I'd make sure to pick a solid flashlight. I don't buy into the whole tactical flashlight concept because a lot of people tend to overemphasize its effectiveness. But as a fistload it can be a good last-ditch option. So would a well made pen or the good old roll of quarters presuming you can throw a good punch.

While it might be off limits in your situation, I would also consider carrying a decent sized flat screwdriver. Not so much as an improvised weapon but if you ever have to pry anything open it might just come in handy. Then again, it might not be a priority to you.