In your Introduction, start it off with your opinion directly stated. Briefly give some reasons or ideas why you agree with your argument. close the introduction restating your argument and add a question like if the topic was clean water your ending statement would be "do you want to drink dirty water".. you get me?
Start off the first paragraph with an explanation for one the brief reasons or ideas you gave in the intro. elaborate on one of the ideas and research your topic to have more evidence for your argument. Do the same thing for the other body paragraphs.
After you have your body paragraphs, make your conclusion. Restate why you support you argument, its basically the introduction but with " In conclusion, this is why i think that______."and then restate the brief reasons.
HOPE THIS HELPS! ;))