This morning I was editing a podcast for a lady, Melissa K Norris. She was recording outside, but one big problem was that she had a strong background noise. I knew there was a way to take it out without taking out the sound of her voice, and that was using the noise reduction.
What you have to do is select a half a second or more (make sure it doesn't have her voice in it, because it eliminates whatever you select to be reduced), then click Effects > Noise Reduction / restoration > Capture Noise Print.
Then you select the whole part in your recording that you want the noise to be taken away (this time it does not matter if the voice is in too) then you click Effects > Noise Reduction / restoration > Noise Reduction (process).
You can then play around with the settings until you have what you want. Once you're finished, click Apply. There you are!