If you don't have a topic already in mind, here are a few ideas of how you might find an issue to consider.
Look at the Opinion section of a news site
Here are two sites you can use:
The New York Times at nytimes.com
As an example opinion pieces on May 4, 2021 cover
whether should enforce lockdowns when they affect the mental health of teens
whether President Joe Biden's spending plans are a good idea
whether the United States should pull armed forces from Afghanistan
CNN at cnn.com
Opinion pieces on May 4, 2021 cover
whether Facebook should continue to exclude Donald Trump
should we continue to wear masks to slow the spread of Covid-19
whether Joe Biden's spending plans will help women re-enter the workforce
Look at the library database called Opposing Viewpoints
You're going to love this site! We'll talk specifics later, but if you're just starting out and want to browse topics, this is the place.
Go to this site and click on the link that says "Browse issues". These will not only be the issues of the day, like the examples above, they also will be long-standing, or big-picture controversies, like cyber-espionage, factory farming, or prostitution.