Bach's 7 Toccaten are virtuosic and improvisatory keyboard works, often serving as preludes to fugues or as standalone pieces. They are characterized by their dramatic contrasts, rapid passagework, and exploration of fugal textures.
Developing evenness and clarity in rapid scalar and arpeggiated passages is paramount.
7 Toccaten is rated Henle level 6 of 9 — advanced repertoire, roughly ABRSM grades 7–8. In the RCM system it corresponds to about level 8.
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.
7 Toccaten is available as free public-domain sheet music on IMSLP — the score is linked directly from this page.