This early set of variations by Mozart demonstrates his precocious talent for melodic invention and his command of Classical style. The pieces explore a range of textures and moods, all derived from a simple allegretto theme.
Focus on crisp articulation and clarity in the rapid scale and arpeggio passages.
8 Variations on an Allegretto (K.24) is rated Henle level 3 of 9 — late beginner repertoire, roughly ABRSM grades 4–5. In the RCM system it corresponds to about level 4.
You should be comfortable at Henle level 3 — meaning you can already play level 2–3 pieces cleanly. Learning it one level early is possible as a stretch piece, but more than that usually leads to months of frustration.
A typical performance of 8 Variations on an Allegretto (K.24) lasts about 8 minutes.
8 Variations on an Allegretto (K.24) is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.