It's okay, I mean, first of all it takes balls to just come out and admit you signed up for a job and are completely green to dj'ing.
Second, it takes balls (or high foolishness) to accept a job dj'ing when you're new to dj'ing.
Third, I did the same damn thing.
I've been producing for two years but have never dj'd; I started a new project and we landed a gig, a two-hour set in July. But since it was July and I knew what equipment I wanted to use, I went for it.
I have Traktor Pro and got a used Hercules RMX a while back off of craigslist. It works great but it left me wanting more options and a different layout, somehow. Then I met a guy who plays w/ Ableton and uses an Akai APC40. And I saw a producer perform with that mixer + Traktor. A week later a guy off of craigslist again was selling his APC40 for a buck 20. I was sold and so was his almost-new equipment.
And now, I "play dj" every day at home. Every day, no matter if I want to or not. At least 20 minutes I tell myself - but it almost always turns into an hour. The more you do it, the better it'll feel, lol.
As to tricks and bells and whistles - I wouldn't worry about it yet. Don't worry about fancy stuff. You will learn (through other people's online instruction) how to beatmatch, and you'll arrange your playlists in such a way so that the songs will work well together and flow. Worry about getting through a solid hour without screwing up. Once you can mix seamlessly, one song into the next, then you can move on to the next level of performance.
Just look up youtube tutorials that instruct using the same software and hardware you're using. And good luck! Practice EVERY day.
Oh - and one more really important thing - DO use Harmonic Mixing. It's a theory, nothing you need to buy. Download a demo of Virtual DJ, it will tell you what key your songs are in, then edit their info in your dj software so you know when to use them. Here's the explanation and a handy color wheel of Harmonic Mixing:
(sorry it's not a link; I'm too new to the forum apparently to be allowed to do that *eye-rollage*)