“Loudness” is subjective (for someone that is totally deaf, nothing is loud). Loudness - Wikipedia
This topic includes some tools for determining various types of “average” measures: "Wave Stats" plug-in
The default view shows the relative levels of the frequencies present in the selection that is being analysed.
If you analyse a pitched note (for example a note from a musical instrument) there will probably be a spike in the graph that is higher than the others, and that will probably correspond to the “pitch” that you hear. It is usually helpful to switch from the Linear to Logarithmic scale (Axis: Log Frequency).
See here for detailed information: http://manual.audacityteam.org/man/Analyze_Menu
“White noise” does not have a “pitch”. It should be a random distribution, such that (over an average) there is an equal amplitude of all frequencies within the test range. White noise - Wikipedia
Due to the random nature, each time that you generate white noise it will be a bit different.