This is a charming, lesser-known character piece by Alexander Kirsch, typical of late 19th-century salon repertoire. It is distinguished by its graceful melody and simple, song-like structure.
The main challenge is achieving an even, legato tone across the light accompaniment textures.
Comparable difficulty and character — good candidates for what to learn next.
'Schön Rosmarin' is rated Henle level 3 of 9 — late beginner repertoire, roughly ABRSM grades 4–5. In the RCM system it corresponds to about level 3.
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 'Schön Rosmarin' lasts about 2 minutes.
'Schön Rosmarin' is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.
Pieces at a comparable difficulty and character include Believe Me, If All those Endearing Young Charms by Irish Folk Music, "s'kommt ein Vogel geflogen" by Siegfried Ochs, Albumblatt by Felix Mendelssohn — see the full similar-pieces list on this page.