Final answer:
The penalty for a first offense of consuming alcohol while under 21 years old and not driving a motor vehicle is typically a 90-day driver license suspension and up to a $500 fine.
Step-by-step explanation:
The penalty for a first offense of consuming alcohol while under 21 years old and not driving a motor vehicle can vary depending on the state. However, the most common penalty is a 90-day driver license suspension and up to a $500 fine. It's important to note that the consequences of consuming alcohol at a young age can have negative effects such as impairment, health issues, and legal consequences.