Johann Baptist Cramer's Op. 39 Sonatas are mature works that showcase his command of the Classical idiom. They demand greater technical proficiency and expressive depth.
Focus on developing a rich cantabile tone and sophisticated pedaling to enhance the sonorous qualities.
3 Sonatas (Op.39) is rated Henle level 6 of 9 — advanced repertoire, roughly ABRSM grades 7–8. In the RCM system it corresponds to about level 7.
You should be comfortable at Henle level 6 — meaning you can already play level 5–6 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 3 Sonatas (Op.39) lasts about 20 minutes.
3 Sonatas (Op.39) is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.