The 8 Little Preludes and Fugues are a collection of works traditionally attributed to J.S. Bach, though their authorship is often debated and frequently attributed to a student like Johann Tobias Krebs. They are essential pedagogical works that introduce students to the fundamentals of Baroque counterpoint and fugal structure.
Developing clean fingerwork and understanding the contrapuntal lines are the main technical challenges.
8 Kleine Choralvorspiele is rated Henle level 3 of 9 — late beginner repertoire, roughly ABRSM grades 4–5. In the RCM system it corresponds to about level 5.
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 8 Kleine Choralvorspiele lasts about 15 minutes.
8 Kleine Choralvorspiele is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.