I would like to be able to isolate specific frequencies/sounds like a specific voice with background noise surrounding it. I want to segregate that one sound and locate all frequencies/sounds like that so I can apply clean-up effects to it like increase amplitute, etc.? Can this be done?
Well, I have good news and bad news.
You don't mention what version of Audition you're using but, if you're on the most recent (Audition CC) there's a very effective frequency band splitter (Edit/Frequency Band Splitter) which lets you split any clip into up to 8 adjustable frequency bands that can be worked on separatedly.
Now, the bad news. Taking your example of a voice, real world sound doesn't give you a nice, specific frequency that you can work on. A normal human voice is going to span from well under 200 Hz up to 8 or 10 kHz--there'll be a "fundamental frequency" (or range) that contains most of the information but the voice won't sound natural without the whole range--think "telephone" or even "AM radio".
Even worse, you're going to find that most noise is also pretty broad band, barring very specific things like 50/60 cycle hum from earthing problems or whatever.
By all means have a play but it may not work the way you want.