I'm new to Adobe Audition and am having some trouble reducing the LOUD background noise in my audio file. We were filming in a warehouse where background noise was unavoidable, so there is banging and forklift beeps and other noises going on as my talent is talking over it all. I've tried looking at videos on how to do this but before I screw it up more than it is I thought I'd see if anyone had any suggestions.
You've got a fast learn ahead of you, for something which is best done with some experience. You're going to find that removing the Noise Floor will get you part of the way, removing the ambient noise - all you need to make sure of is that you have a point in your production where the only sounds there are the background sounds. You take a Noise Print from that, then remove it from the whole clip - bear in mind that you never want to remove all of the ambience - then you might as well shoot in a library. Here's a good education in the Adobe Audition help files: http://help.adobe.com/en_US/audition/cs/using/WS58a04a822e3e501054824103898...
The beeps and bangs will have to be removed in a different way, which is also discussed in the above. You'll want to find them in the Spectral Display, then remove them. The good noise there is that things like beeps will most likely be in the identical part of the sound spectrum - so once you nail one, you can easily get them all. Good luck!
That said, I think once you remove all the things you're talking about removing, I doubt you'll have much left. This isn't magic. Taking out a constant background rumble or buzz can work pretty well. Removing the occasional bang or beep in the background is great. If there's very much of it, though, you'll end up removing the voice you want to keep along with the background sound. There's no substitute for getting better sound when recording it. If the level of the voice you want to keep is WAY above the level of the background noises, then you are far better off and might not need to remove much of anything. So in this case, you might need to use what Ty Ford calls the "reshoot filter". That is, you may have to re-record in an environment where the voice is not drowned out by background noises.