The closest thing in Audacity to what you are looking for is probably "Beat Finder". This tool tries to work out where the beats are in a piece of music, based on the amplitude of the signal, and places a label at each beat. However, it is easily confused by pauses in the music, or any change from a regular beat.
Another tool that may be useful is "Regular Interval Labels" (Not available in 1.2.x), which will place labels at intervals you specify. It might make it easier to line up the notes to the beat.