I am operating on Windows 10. I live in a basement condo unit and have a very noisy teenager living in the condo immediately above me. I have set up a Blue Yeti microphone about one foot under my ceiling to record the kid’s noise when he stomps. I am using Audacity software. I am a pure newbie as far as using Audacity goes. The Blue Yeti microphone is very good at recording noise and sound within the same room or even rooms on the same floor. The problem I am having is that it does not record noises in the adjacent room above me very well. When I record, the kid’s loud stomping sounds like a cat barely scratching something. I wanted to use the “amplify” function off of the “effects” toolbar to boost the stomping sound so it is more accurate. What numbers do I need to plug into the Amplify panel to maximize the sound? I read the manual directions and they are confusing. I assume I can amplify sounds on both old and new files. Any information provided would be appreciated.
A home recording is not good evidence of noise pollution. It would certainly not stand up in court.
You need a calibrated “Sound Pressure” meter - they are very expensive, but environmental health organizations will have them.
Amplify to boost the the “digital maximum” of 0dBFS. If the peaks are already hitting the maximum it won’t amplify anymore unless you click the Allow Clipping (allow distortion) box. Or, you can use the Limiter effect with make-up gain to boost the overall volume without boosting/clipping the peaks.
And of course, bigger speakers and bigger amplifiers will go louder than small speakers and small amps… It may be more of a playback issue than a recording issue, especially with low-frequency “stomping” sounds.
The problem I am having is that it does not record noises in the adjacent room above me very well. When I record, the kid’s loud stomping sounds like a cat barely scratching something.
The Yeti does have some directional settings and it may not pick-up sounds from the end/top with any setting so make sure the mic is facing the ceiling.
When the amplify effect starts, it determines this “maximum” value for you automatically. 
The default settings will do what you are asking for here.