Some sources of ‘famous’ datasets you can use to practice:

• R package agridat [link]
  Highlights:
  • cochran.crd Potato scab infection with sulfur treatments. Completely randomized design.
  • besag.met Multi-environment trial of corn, incomplete-block design.
  • durban.splitplot Split-plot experiment of barley with fungicide treatments.
  • cox.stripsplit Strip-split-plot of barley with fertilizer, calcium, and soil factors.
  • gomez.splitplot.subsample Split-plot experiment of rice, with subsamples