Simply finding frequency of a sound

For a science project I’m doing, I need to find the frequency of a wineglass when it vibrates. I downloaded Audacity to do that but I’m a little stuck. I tried testing the software by taking my pitch pipe and playing an A to the program (which should be 440Hz) and then found the plot spectrum and got a graph but I don’t need to know the dB of the sound and it should only be one frequency. Is there a frequency over time graph I can use or something? A trick to get the frequency?

If you move the mouse pointer into the graph in the Audacity “Analyze > Plot Spectrum” window, the “Position” and “Peak” values appear below the graph.

Not true! It will be the 440Hz “A” plus a whole load of harmonics from the pitch pipe and from room reverberations. Result: A “fuzzy” spectrum - but with a distinct spike at 440Hz.