The title 'To the Sun' suggests a bright, radiant, and perhaps virtuosic piece, likely full of energy and optimism. Its musical distinctiveness would stem from its luminous harmonies and spirited melodic content.
Practice clean articulation and controlled speed to achieve a brilliant and sparkling effect.
Au soleil (Op.17) 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.
Au soleil (Op.17) is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.