Recommendation for creating a graphical timeline representation
A simple way is to use the SmartArt feature in various Microsoft Office programs (e.g. PowerPoint) to create a timeline. Google Slides can also be used (Insert -&gt; Diagrams -&gt; Timeline). See e.g. this guide for more details and inspiration. Alternatively, as henning states in a comment, you can just use a generic drawing app.
TeX solutions also exist, and have been described on other stacks. See e.g.

How to create a timeline with LaTeX?
How do I develop a complex time line?
How can you create a vertical timeline?