Lawrence D. Guth lectures on random walks on finite groups as part of MIT's 18.156 Projection Theory course. He gives an introductory treatment of the subject, building up the basic framework before turning to two major results: Selberg's theorem and the Bourgain-Gamburd theorem. The lecture situates random walks on finite groups within the broader toolkit of projection theory, showing how spectral gap and expansion properties of groups connect to questions about mixing times and equidistribution. As with the rest of the course, the approach is chalkboard-based and proof-driven, aimed at graduate students with background in analysis and group theory. This is the first part of a two part treatment, laying groundwork that the following lecture will extend further into the Bourgain-Gamburd machinery.