If you outgrow Audacity's built-in tools, install these free VST plugins (Audacity supports VST3 on recent versions):

Click the "Preview" button to hear the autotuned vocal recording. If you're happy with the result, click "OK" to apply the effect.

– Go to Effect > Pitch and Tempo > Plot Spectrum... to see the dominant frequency. Alternatively, use a free pitch detection plugin or your ear.

Download GSnap from the GVST website. For older versions of Audacity, ensure you download the 32-bit version.

– Go to the top menu: Effect > Pitch and Tempo > Pitch Correction...