While onboarding an open source software (OSS) project, contributors face many different barriers that hinder their contribution, leading in many cases to dropout. Many projects leverage the contribution of outsiders and the sustainability of the project relies on retaining some of these newcomers. In this research, we aim at understanding the barriers that hinder onboarding of newcomers to OSS projects, by means of different empirical approaches, and proposing a set of strategies that can be used to support the first step of newcomers.