This K.179 work by Mozart is a charming set of variations on a minuet by Fischer, written for piano solo. It is distinguished by its melodic inventiveness and the skillful exploration of different musical characters within the variations.
Focus on evenness of touch and articulating ornamental figures clearly within a smooth legato framework.
12 Variations on a Minuet by Fischer is rated Henle level 5 of 9 — late intermediate repertoire, roughly ABRSM grades 6–7.
You should be comfortable at Henle level 5 — meaning you can already play level 4–5 pieces cleanly. Learning it one level early is possible as a stretch piece, but more than that usually leads to months of frustration.
12 Variations on a Minuet by Fischer is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.