This collection, arranged by Casella, offers accessible Baroque repertoire, likely focusing on contrapuntal texture and clear melodic lines from Bach. They serve as pedagogical tools for early keyboard study.
Focus on clear articulation and the separation of melodic voices.
23 pezzi facili (Casella) is rated Henle level 2 of 9 — beginner repertoire, roughly ABRSM grades 2–3. In the RCM system it corresponds to about level 2.
You should be comfortable at Henle level 2 — meaning you can already play level 1–2 pieces cleanly. Learning it one level early is possible as a stretch piece, but more than that usually leads to months of frustration.
23 pezzi facili (Casella) is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.