First, download Obdisian. https://obsidian.md/
Second, open folder as vault.
Then, open and customize graph viiew.
Let's say there is a file named "CS_410.md" and another file named "text retrieval.md". The way to create a link between them is to write "[[text retrieval]]" in CS_410.md or to write "[[CS_410]]" in another file. These two ways should create links with different direction.
Note that file names should end with ".md".
An example is in week07/course_concepts/. If you set it as a vault in Obsidian, you should be able to visualize the links with "graph view".