They also fear having personal space invaded by a “randomer” sitting next to them when other seats are free.
Research by passenger watchdog Transport Focus found young people’s experience of bus travel was “regularly disappointing”.
Other complaints included grumpy drivers, dirty seats, and unreliable services, with some regarding the bus as a “last resort”.
The research, conducted in England, was presented at an event in Glasgow by the watchdog, which said that getting the bus was an “essential life skill”, but early experiences could “deter future use”.
Transport Focus said those 14 to 19-year-olds who regularly used the bus were more positive, regarding it a good and cheap way to get about.
However, Louise Coward, its acting head of insight, said young people lacked understanding of how buses worked.
These included what fares were called and which one to ask for, how much they cost, and how to know when to get off the bus.
She said: “There is an enormous fear of getting things wrong and not wanting to look an idiot in front of the bus driver. Some say they have to check Google Maps on their phones to see where they are.”
Ms Coward said teenagers could not understand why they could order a pizza and track its progress on their phones but could only find the cost of a bus fare by getting on board.
She added that space on their phones was limited, and bus apps had to earn their place by being seen as valuable.
Ms Coward said young people also noticed details like cleanliness, with comments like “Why should I have to pay to sit on those seats when I’m wearing my new jeans?”
By contrast, she said Uber was a “real pull” among 17 to 19-year-olds for its convenience in being able to book and pay in advance, with no interactions required.
The Scottish Government’s Transport Scotland agency said measures in the transport bill being considered by MSPs would require operators to provide more fares and timetable information.
Peter Grant, its interim head of bus policy, told the event he had been “quite struck” by young people finding accessing bus information harder than ordering pizzas.
However, he admitted: “Sometimes it’s really difficult to get your head round how to get a bus from here to there.”
Sharon Morrison, commercial manager at bus operator West Coast Motors, who attended the event, said: “It was interesting to hear the findings, especially young people’s experience and perception of travelling by bus.
“Whilst we recognise the research was carried out in England, there is definitely learnings we can take to ensure we are reaching our younger customers and meeting their travel requirements.”