Neutral term for someone new to a skill, activity, or field. Often used in contrast with 経験者 or 上級者.
I'm still a beginner, so please teach me slowly.
このコースは初心者向けに設計されています。
This course is designed for beginners.
He is a beginner at tennis.
Even beginners can make it easily.
I bought some beginner-use tools.
初心者 focuses on lack of skill or experience regardless of tenure, while 新人 focuses on recent membership in a group or organization.