These databases can find all types of articles and multi-modal resources. However, they are best at finding academic research articles. Do you need a scholarly or peer reviewed article? It's a good idea to begin here.
Major subject headings or tags:
Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the government for a redress of grievances. Legal Information Institute, U.S. Constitution, First Amendment, available at https://www.law.cornell.edu/constitution/first_amendment
What the First Amendment Guarantees .... "The First Amendment guarantees freedoms concerning religion, expression, assembly, and the right to petition. It forbids Congress from both promoting one religion over others and also restricting an individual’s religious practices. It guarantees freedom of expression by prohibiting Congress from restricting the press or the rights of individuals to speak freely. It also guarantees the right of citizens to assemble peaceably and to petition their government."
[Legal Information Institute, First Amendment, available at https://www.law.cornell.edu/constitution/first_amendment]
"SCOTUSblog is devoted to comprehensively covering the U.S. Supreme Court without bias and according to the highest journalistic & legal ethical standards." [About SCOTUSblog]
These are examples of multimodal information sources. There are many other types of multimodal information and writing. Please consult with your writing instructor about how to incorporate multimodals into your writing assignment.
A highly selective sample of non-governmental constitutional law policy and research making organizations -- Other unlisted sites may prove equally valuable and valid for purposes of your research.