Junk Fee Prevention Act This bill establishes requirements related to the fees charged by specified covered businesses, including those providing short-term lodging, ticketing services, internet service, mobile service, or video programming. It also requires air carriers to seat each young child next to an accompany adult during flights. Specifically, businesses providing short-term lodging or ticketing services must display the total price (including mandatory fees) of the offered good or service in each advertisement and when the price is first shown to the consumer. Further, ticketing services must (1) disclose any guarantee or refund policy for an event before the transaction is completed, and (2) disclose when they do not possess the ticket for an event at the time of sale. The bill also prohibits excessive or deceptive mandatory fees and provides the Federal Trade Commission and state attorneys general authority to enforce these requirements. Additionally, the bill prohibits internet service, mobile service, or video programming providers from charging excessive or unreasonable termination fees. The Federal Communications Commission (FCC) also must conduct a rulemaking to consider requiring such providers to disclose mandatory fees or prohibiting the services from imposing mandatory fees. The bill provides the FCC authority to enforce these requirements. Finally, the bill establishes requirements for air carriers to seat each child who is age 13 or younger next to an accompanying adult, subject to limited exceptions. The bill also requires air carriers to provide specified alternatives or a full refund in the event that such seating is not available.