I won't write the whole paper for you but I'll give you a bite.
Let's do a simple subject, alcohol.
1. Brief description - make a not-too-short-but-not-too-long description of alcohol.
Go to Wikipedia about alcohol.
"An alcoholic drink (or alcoholic beverage) is a drink that contains ethanol, a type of alcohol produced by fermentation of grains, fruits, or other sources of sugar. The consumption of alcohol plays an important social role in many cultures. Most countries have laws regulating the production, sale, and consumption of alcoholic beverages."
2. Side effects - think about the bad things that alcohol would do to a person.
"Alcohol has significant negative health effects, including increased risk of death and cancer. Negative effects are related to the amount consumed with no safe lower limit seen." - Wikipedia
3. Why alcohol is dangerous - well it's the same as side effects but might as well add an argument to mostly avoid alcohol (Because it would kill someone; for example, drinking and driving)
4. Sources of help for someone wanting to overcome an addiction to that drug.
Visit this site
https://www.helpguide.org/articles/addictions/overcoming-alcohol-addiction.htm
<em>NOTE: Do not copy the source materials without citing them (show the website where you got that information from</em>). <em>For example Wikipedia. This answer will just give you the idea</em>.
Hope this helps