It sounds like you are going to get set up for disappointment. Headshots should be consistent for everyone at the office. But …

At a party, people are getting progressively more drunk.
The indoor office lighting is rarely flattering.
Natural lighting (assuming it is during the day) is always changing adding additional challenges to keep one head shot the same as the next.

There is a YouTube channel with a good guide on “the Slanted Lens”. There are many more guides on YouTube for you to get the information you need.

I would just say no. It’s your holiday party. Enjoy the party. Don’t get roped into working. Unless you want to get into headshots. In that case, rent yourself a set of studio lights for the evening, watch a couple of YouTube videos, find a plain wall, and get your feet wet. If they complain, tell them you get what you pay for. They could’ve hired somebody with headshot experience, but they asked you to do it for free. You’ll probably get a handful of keepers to use to get your first actual gig, and then it’s all rise from there. In theory, anyway.

Ask your office to purchase a backdrop and a lighting setup for you at the very least. You can get a basic cheap continuous lighting softbox and a backdrop for about $200.

Use weird angles and call it artistic and if anyone complains tell them they don’t get it, easy peasy Fuji

Don’t do it.

You might think you’re going the extra mile and doing a favor for your employers. But at the end of it, you will have (through no fault of your own) wasted a lot of people’s time and NOT gotten the results your employer wanted.

That’s what your employer and co-workers will remember… not that you were trying to go the extra mile to help, but that you took on a task you weren’t qualified to deliver on and squandered a lot of people’s time.

Ask me how I know.

I also have no lighting to use and am hoping that the natural lighting is good on the day of the event

Oh man, prayers for you. This is not the way haha

Ask for them to pay to pay for lighting equipment and do not for free. That way you get some equipment out of it and some great experience and portfolio.

So…they requested you work at the holiday party. And do something you are not qualified to do.

Just say no, and explain you aren’t really able to do so.

set up a camera on a tripod, and you need lighting it’s just a fact. that lighting could be from two lamps as long as they’re consistent and behind the person with a softer light on their face.

you can work that out in any number of ways, it’s best to have a seat or chair set up and light the background, then the subject and meter for their face.

headshots would be about shoulders and up so a 50mm with bokeh would be great, you want to treat it like picture day at school, if the settings and lighting are kept the same then you can just hit the shutter button and funnel them in and out. I wouldn’t recommend doing this unless you have a controlled light source and a space where the background won’t be changing constantly.

I’ve done natural light headshots that I liked, but I got to specify the location and exact time I wanted, in a place I knew the lighting. You’ll have none of this.

Conversely, if they’ll pay you, rent two octaboxes or bounce umbrellas and a couple speedlights.

This sounds like clusterfuck waiting to happen. Headshots at a party? Who’s going to be suited for what I assume to be a professional headshot. They are setting you up for failure by not just ponying up the money for a professional photographer. Not saying you couldn’t learn how to do the job, but on so short notice, with your lack of experience and equipment, it’ll end up with subpar results.

Yeah no, don’t do this. Anyone offering you advice is coming from a “if i was there I could do it” mentality but the reality is that you’re being forced to learn how to do something with no training and no equipment in a short amount of time. You do a good job and now you’re the camera guy. You do a bad job and everyone will remember you for it.

The only way to win is to not play.

They asked you to work during the holiday party?

Are they paying you holiday wages?

Other posters are probably correct, if you have never done this before, this is not the time to experiment. Learn how to light a portrait and practice before you attempt a task where others expect professional results. A great place to start is with this series on lighting by David Hobby, the Strobist.

https://strobist.blogspot.com/2006/03/lighting-101.html

Follow Peter Hurley. The undisputed headshot KING.