Little is known about the emotional experience of children and young people during lockdown, their coping strategies on COVID-19 pandemic context and their influence on the emotional state when dealing with the challenges associated with lockdown. In this study, 1031 children and young people (865 aged 8-15 years old and 166 aged 16-25 years old) answered an online self-report survey, specifically designed to assess the perceived potential contribution of SES learned/developed in the Gulbenkian Academies for Knowledge—a national initiative—in coping with the consequences of the context of the COVID-19 pandemic during the Portugal first lockdown. There are three main findings. First, the prevalent emotional pattern was predominantly negative (53.7%) for the younger participants (most frequent emotions: boredom 66.9%; worry 47.8%) and predominantly positive (52.0%) for the older participants (most frequent emotions: boredom 70.1% and tranquillity 52.6%). Second, school activities (25.2%, 8-15 subsample; 32.7%, 16-25 subsample) and self-knowledge and self-regulation activities/strategies (24.8%, 8-15 subsample; 20.0%, 16-25 subsample) were the most frequently reported by participants from both subsamples and that this has significantly interfered with their emotional state: among 8-15 subsample, they reported feeling more excited, more calm, more optimistic and more hopeful; among 16-25 subsample, they reported feeling more cheered up, more optimistic, more quiet and more hopeful. Culinary and horticultural activities predict about 4% the possibility of feeling hope, sadness, optimism, irritation, and worry (8-15 years old) and school activities contribute about 17% to the explanation of the emotional states of sadness and optimism (16-25 years old). Third, both the younger and the older participants showed a medium-superior level of socio-emotional skills and those SES predict about 20% the possibility of feeling optimistic, irritation, sad, hopeful, and bored (8-15 years old) and about 12% the possibility of feeling sadness (16-25 years old). The potential of social and emotional skills in exceptional circumstances and vulnerabilities are discussed.