The workshop will focus on various aspects of the theory of group actions from a probabilistic perspective, with a particular emphasis on random walks on groups. At the crossroads of probability, geometry, and ergodic theory, the theory of random walks on groups is a very active research field, centering on the interplay between the algebraic properties of the group and the dynamical properties of random walks on it. Among the themes of the workshop, we will explore applications of these methods to geometric group theory and geometric topology, in order to study properties of random geometric objects, as well as their relation to the notion of amenability and the theory of Poisson and Martin boundaries.