The first should start with an introductory sentence or two. Normally an entire paragraph can be dedicated to such purposes, but the above will work for this scope. After telling your audience what the passage is about, give an educated opinion of what you want to discuss as a way to give a personal touch to the proceedings. This helps to avoid exceedingly analytical or rote writing, as in a spreadsheet or outline.
The final 2-3 sentences of the first paragraph should be fact-based and expand in a chronological order, making the paragraph easy to follow for those unfamiliar with the subject. Writing this way will also help to avoid repeating yourself, which can happen fairly easy.
The 2nd paragraph should elaborate on a chosen point within the theme you are covering in the first paragraph. For example, if you are writing about World War II, this paragraph can narrow the focus to the Allies or the Axis Powers. A broad established theme, that interests the writer, will galvanize their efforts to write more as the paper goes on, making it evident that the author is passionate about the subject, and subsequently, more interesting for the reader. Concluding with this method also make a path for more themes to be explored if the paragraphs are expanded into a paper or utilized for another assignment in the future.