The writing stage is often called drafting. When you draft, you should be focused mainly on ideas, rather than worrying too much about your grammar. Use your outline as you draft to make sure you don't lose your focus.
You should not simply paste several quotes together into one body paragraph. Consider which pieces of your quotes are necessary to support and develop the topic sentence. This means that some pieces of quotes may be unnecessary because they don't support the topic sentence. It's also okay to divide large quotes into smaller quotes that focus on smaller ideas.
You will also need use your own words to connect quotes together. You will use your commentary to introduce some of your research, explain how a quote supports your topic sentence, explain what a quote means, or show how quotes are connected together.
After you use a quote, don't simply summarize it; remember to justify or clarify the reason for using the quote.