Answer:
When writing an argumentative essay there are a few steps you need to take to organize it before you really start writing.
Step 1: Choosing A Topic; you need to figure out what argument you're basing your essay on.
Step 2: Research; using credible sources, find information to support your claim(ie; books, articles, and documentaries)
Step 3: Outline; draw out how you will structure your essay and how you will use the information that you've gathered.
Step 4: Fill In the Blanks; If you correctly did the previous step and wrote a well-developed outline, all you have to do is fill in the blanks with relevant research details.
Explanation:
Those are the steps before you begin writing an drafting your essay.
So to answer your question, you gather evidence before creating your outline.
✨I hope this helps!!✨