A key for learning anything is being curious and exposed, in combination. A great way to get that as a beginner (in coding or in a new environment) is to take on bug fixes and CRs. While not always everyone's favourite it forces you to dig into others code, see things you like/dislike, grok new concepts, and challenge the inner-you with doing what's right vs. what is faster. Perfection vs pragmatism - knowing what to side with and when is a key to a long career.