Hans Christian Lumbye's 'Anna Vals' is a charming and melodious waltz. It captures the elegance and grace of the ballroom dance with its flowing melodies and characteristic three-four rhythm.
Focus on achieving a smooth, singing tone and a natural sense of rubato.
Anna Vals is rated Henle level 4 of 9 — intermediate repertoire, roughly ABRSM grades 5–6. In the RCM system it corresponds to about level 6.
You should be comfortable at Henle level 4 — meaning you can already play level 3–4 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 Anna Vals lasts about 3 minutes.
Anna Vals is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.