Cursive was created many moons ago to improve the efficiency of writing. The goal is to write the whole word without lifting your pen or pencil up unless you have to. Your handwriting may be cursive or a mixture of print with cursive and you may feel it looks sloppy, therefore, you could never do calligraphy.
Well that’s false! I have sloppy handwriting too!
Calligraphy should be looked at as an art form and you learn different strokes that form letters. Between strokes you also lift your pen, unlike curse, so it will give you much better control of the thick and thin lines in your strokes.