Regardless of the time of day you decide to fly, the ticket price will remain around the same. Book flights from Penang to Guam as you normally would.
Related info for your journey
Useful info, stats and facts about Penang to Guam flights.
Penang Intl (PEN) is the airport you will fly out of if you book a flight from Penang to Guam. It is only a 14.5 km journey to Penang Intl (PEN) from Penang’s city centre.
These are just IATA (International Air Transport Association) codes. They are used in aviation to identify and differentiate airports. That’s why a Penang Intl Airport to Tamuning Guam Intl Airport flight would often be abbreviated as a PEN to GUM flight.