One of the biggest problems that beginning writers have is developing strong, consistent body paragraphs. A body paragraph needs to address a specific topic. Many young writers will put many different ideas in the same paragraph, or will stray from writing about what the paragraph is intended to be about.
To correct this common error in writing, go back when you’re done and break each paragraph down. Does your paragraph address the same topic throughout? If it doesn’t try adding another paragraph to separate you ideas into separate paragraphs.