Both destinations are served by Dabolim Airport (GOI). Since there's no flight route between them, the best way to travel is by road.
Goa
Fly to Dabolim Airport (GOI), then travel by road to Goa. Taxis, buses, and private cabs are available from the airport.
Udupi Railway Station
Fly to Goa (GOI), then travel by road to Udupi Railway Station. Local transport options include taxis, auto-rickshaws, and state buses.