My teacher didn't really specify, I know the thesis statement goes first but are you suppose to then write your opinion?

Do you have a topic in mind? (first order of business)

Yes, you will need to support your thesis.

Once you know what you're going to write about (the muscles and flesh of your outline), then start filling in thoughts and ideas in this outline (the skeleton of your essay):

Title (Centered)

I. Introduction
A. Thesis
B. Statement of points

II. Body
A. Point 1
1. Supporting Information
2. Supporting Information
B. Point 2
1. Supporting Information
2. Supporting Information
C. Point 3
1. Supporting Information
2. Supporting Information

III. Conclusion/Summary
A. Summary of supporting information
B. Conclusion reached (Restatement of thesis)

IV. Citations (if needed)