The US Census Bureau is a versatile source of information on your district. Besides the well-known decennial Census and the annual American Community Survey, the Bureau conducts over a hundred other surveys each year, touching on race, economics, housing, retail, education, criminal justice, local government, and more.
Use the data.census.gov website or the library's Social Explorer subscription to view this wealth of data on a map of your district.
Here's a Social Explorer map showing that the 2019 American Community Survey estimated the median household income in the 13th Congressional District to be $64,779.
Take note of major cities and population centers in your district. Try searching online or in a library news database to find out how local newspapers cover the district. What kind of issues keep recurring? How do these stories cover your Representative?
One caveat - finding local news coverage of politicians is becoming more difficult. Over the last twenty years, shifting business models forced many local newspapers to shut down or be bought out by private equity firms. Several providers now monopolize the news landscape, allocating reporting to stories that generate online views, reducing coverage of politics, particularly at the local level, and syndicating stories across multiple papers to maximize revenues. For more information on how journalism is changing, see my Open Educational Resource, Guide to Library Research in the Arts.
Many news articles that you find online or linked from social media posts are paywalled. This can be an indicator of quality: many reputable news outlets instituted paywalls in the 2010s to be able to retain and compensate a staff of trained reporters. To get around the paywalls, you can look up the full text of the articles you found in the library's subscription news databases.
Rep. Pete Aguilar of the California 31st Congressional District - University of Redlands' home district - is our example Representative for the sample searches throughout this guide.
Practice finding information on Rep. Aguilar so that you can apply similar strategies to learn about your member once you've received the assignment.