There are a lot of terms used to identify a beginner — many of them condescending or derogatory, so pay attention to connotation before employing any of these synonyms:
1. Abecedarian (from the Latin term abecedarius, “of the alphabet,” coined from linking the first four letters of the alphabet with vowels to form a pronounceable word): One in the early stages of learning.
2. Amateur (from the Latin term amator, “lover”): Someone who engages in an area of skill or expertise without remuneration, or, derogatorily, a person without experience or ability.
3. Apprentice (from the Latin term apprendere, “to learn”): One in the midst of hands-on training; originally denoting someone bound by a contract to train with a craftsperson, but now employed simply to refer to someone inexperienced. The term is used in a naval enlisted rank (“seaman apprentice”) and for the lowest level in Freemasonry (“entered apprentice”).
4. Babe (from the Middle English word coined in imitation of baby talk): An inexperienced person, with a condescending connotation of naivete.
5. Boot (from Anglo-French bote, “boot”): A US Navy or US Marine Corps recruit, perhaps from “boot camp”). Condescending.
6. Colt (from the Old English term for a young horse): A young, inexperienced person. Condescending.
7. Cub (from the word for a young animal): A young, inexperienced person, as in the expression “cub reporter,” referring to a new journalist. Condescending.
8. Fledgling (ultimately from Old English fleogan, “to fly”): Originally, use was confined to the literal meaning of “a young bird just learning to fly”; now, it is also a rare informal, condescending term for a young, inexperienced person (and is used to refer to a new enterprise).
9. Freshman (derived from fresh, as in “new to a situation,” and man): Originally referred only to a first-year student; now also denotes a politician or an athlete at the beginning of their career.
10. Greenhorn (from an obsolete English word referring to the new horns of a young horned mammal): Refers not only to a naive, inexperienced person but also to someone unfamiliar with customs or procedures. Condescending.
11. Layperson (from the Latin term laikos, “of the people”): A non-gender-specific variation of layman, originally denoting someone who is not a member of the clergy but now a general reference to someone who is not part of a particular profession or does not have expertise in a given subject matter.
12. Neophyte (from the Latin term neophytus, “newly planted” or “newly converted,” from the Greek word neophytos): A beginner or a convert. Mildly condescending.
13. Newbie (a diminutive noun derived from new): A person new to a place or situation, especially one unfamiliar with the conventions and etiquette of online interaction; a newer diminutive of this slang term is noob (or n00b, using zeros instead of the letter o, a variation often used in online conversation). Condescending or even derogatory.
14. Newcomer (a compound noun formed from new and come): Originally, one newly arrived to a location, but now a beginner in general.
15. Novice (from the Latin term novicius, “newly imported”): Originally, a probationary member of a religious organization, now generally someone with rudimentary skills. Depending on context, can be condescending.
16. Novitiate (see novice, above): A variation of novice, as well as a word for the condition of being a clerical novice, or the name of their residence.
17. Proselyte (from the Latin term proselytus, “foreign resident,” derived from the Greek word proselytos): A recent convert.
18. Probationer (from the Latin term probare, “approve”): Someone in the process of learning.
19. Punk (origin obscure): A young, inexperienced person, though it also has connotations pertaining to punk subculture and to sexuality. Derogatory.
20. Recruit (from the French term recrute, derived from recroistere, “to grow up again”): A newcomer; often used in a military or similar context. The term is used in the lowest naval enlisted rank (“seaman recruit”). Depending on context, can be condescending.
21. Rookie (uncertain; perhaps derived from recruit): One in his or her first year or years of experience, originally in the context of professional sports but now general in usage. (The back-formation rook is rare.) Depending on context, can be condescending.
22. Tenderfoot (a combination of tender and foot): Originally, someone new to a frontier area, unused to hardship; in the modern sense, a beginner. Condescending.
23. Trainee (from the Latin term traginare, “to draw” or “to train”): One learning a job or skill.
24. Tyro (from the Latin term tiro, “young soldier”): An inexperienced person.
25. Virgin (from the Latin term virgo, “young woman, virgin”): Originally a specific reference to a female with no sexual experience, now used lightheartedly to refer to someone new to a situation.