An amateur shouldn't play professional poker for high stakes.
Steve's father was an amateur gardener who readily admitted he was a neophyte, really just a tyro, when it came to raising certain bulbs; however, he carefully studied the armature of the corm of each of the species before planting them.
Additional clarifications regarding amateur, neophyte, novice, and tyro
Amateur, the most widely used of these four terms, is applied to someone who follows or pursues any art, study, or other activity simply from the love of doing it.
In certain activities; especially, sports, an amateur is anyone who, regardless of excellence, receives no payment for his or her performance: Alice played as an amateur for five years before becoming a professional.
Neophyte also refers to a beginner (novice, tyro), but the term is usually applied to a recent church convert; especially, to a novice in a religious order and to a recently ordained priest.
A novice is a beginner, a person new to any field or activity: Some young brides are novices when it comes to housekeeping.
Tyro is closely related in meaning to novice; because it refers to someone who is inexperienced: James was a tyro during his first weeks at training camp.
An amateur may be skilled and even experienced, but neophytes, novices, and tyros never are. A neophyte, novice, or tyro may be a professional, but an amateur never is.