A topic sentence presents the main gist of the whole paragraph or article. So, if you want to talk about building a snowman, your topic sentence could be about why building snowmans are of relevance. Then, your supporting details could now include steps or advices on how to build it.
A good topic sentence I could think of is:
<em>During the yuletide season, building a snowman is a good activity to do with family and friends because it promotes team-building and fun interaction.</em>
Answer: inferred
An inferred meaning is one that is not explicitly stated by the author, but that is hinted at throughout a passage. This is usually done through the use of various rhetorical and literary devices, such as characterization, symbols, motifs, setting and mood.
The figurative language is personification