This early Allegro by Mozart, K.5a, is another delightful work from his prodigious childhood output. It's characterized by its clear melodic structure and youthful exuberance.
Focus on clear phrasing and precise articulation, especially in the Alberti bass patterns.
Allegro in C major (K.5a) is rated Henle level 1 of 9 — beginner repertoire, roughly ABRSM grades 1–2. In the RCM system it corresponds to about level 2.
You should be comfortable at Henle level 1. 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 Allegro in C major (K.5a) lasts about 1 minute.
Allegro in C major (K.5a) is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.