Purpose: The purpose of this study is to explore beginning teachers' diverse challenges and how these are related to self-directed professional learning through social media. Design/methodology/approach: The authors conducted a content analysis of 2,445 "New Teacher" tagged posts shared in the r/Teachers subreddit. With 1,246 posts relevant to beginning teachers' challenges, the authors used a socio-ecological model to analyze and categorize the challenges. Findings: Results showed that posts reflected diverse and complex challenges. Such challenges were found to be interrelated and associated with employment status, highlighting teacher marginalization issues. Results also show that most posts sought resources or advice rather than merely complaining about their situations, meaning that beginning teachers leveraged the anonymity and shared affinity offered by r/Teachers to overcome their challenges as self-directed professional learners. Originality/value: The current study not only highlights diverse and complex challenges faced by beginning teachers but also sheds light on how they navigate their challenges in social media spaces. This research provides unique insights into how social media, particularly an anonymous affinity space -- r/Teachers, can benefit teachers' professional growth in today's digital era.