With this Training Course, we wanted to support youth workers in assessing young people's well-being, socialization, and prevention of marginalization through the concept of sustainable youth work on two meta-levels: internal - youth work as an individual and professional, and external - youth worker and other target groups (youth, colleagues, representatives of other target groups). Our goal is to improve the quality of youth workers at the internal and external levels, thereby improving the quality of Erasmus+ projects at all stages, developing practical recommendations for preventing marginalization and contributing to the socialization of youth, which will be disseminated among partners in the SALTO Toolbox for Training & Youth Work for common use by youth workers from different countries. We also wanted to develop the skills and attitudes of youth workers to strengthen their personal and professional impact and help young people build social stability and prevent occupational violence, and to be able to help young people build social stability and anti-marginal resilience in their environment. Objectives: - To find a common definition and develop practical recommendations for preventing youth marginalization; - To equip youth workers with the knowledge and tools to work effectively with youth with fewer opportunities using non-formal learning; - To share common knowledge on a variety of international experiences on solutions to specific problems, how to counter youth marginalization and exclusion; - To increase the competence of youth workers in disseminating educational achievements within youth NGOs and youth work at local, national, and international levels; - Support youth organizations in increasing the capacity of their work and thus becoming better at improving their future work, especially in the context of the Erasmus+ program; - foster networking and quality improvement among participants, and create space for project development through international cooperation. Thereby, our project will increase the competences of the youth workers and capacities of the organizations from different countries working in youth field, will equip youth workers with competences and methods needed for transferring the common values on local, national and international level.