Specifically "Wechselpräpositionen" (two-way prepositions) that take either Accusative or Dative.
Downloading a hundred PDFs won't make you fluent—doing them the right way will:
These are the two major textbook publishers in Germany. Look for their "Downloads" or "Materialien" sections. You can often find grammar overviews and extra vocabulary lists for the A2 level for free. How to Use These Worksheets Effectively
This is often the "boss level" of A2. You'll practice how endings change based on the case and the article.
