Native installation packages for your platform can be downloaded from Audacity Download (http://audacity.sourceforge.net/download/).
The first time you attempt to export an audio clip into mp3, you may be asked to locate the file lame_enc.dll; to obtain a copy, go to Lame library download. You may need to unzip the file.
The default settings is suitable for most purposes; if you wish to view or change any settings, go to Edit > Preferences.
Notice two leftmost buttons; the top one is the and the bottom one is the . Round buttons are used for playback control, the red dot starts recording. The yellow square stops the recodording.