Inside the city
Grab covers almost every trip you will take in the first month. A car across town is often in the 60,000–100,000 dong range. A bike is roughly half. Prices move with rain and rush hour. If you are only here for a few weeks, this is enough.
A scooter becomes worth it when you are staying and you are leaving the beach grid. Monthly rental commonly sits around 800,000–1,500,000 dong depending on the bike. You need a licence that police will accept. An international driving permit plus your home licence is the combination people are told to carry. Check the current rule before you ride, and do not treat a Facebook comment as the law. Traffic is orderly by Vietnamese city standards and still faster than a newcomer expects. Helmet on. Rain turns the beach road slick.
Airport
Da Nang International is in the city, not an hour outside it. A Grab to My Khe or An Thuong is a short ride. Agree the app price rather than a kerbside negotiation.
South to Hoi An
About forty minutes, depending on where you start and on the bridge traffic. A taxi from the airport to Hoi An is often quoted around 350,000–450,000 dong. From the beach, Grab works for a day trip. If you do it every week, the scooter maths changes.
North to Huế
The Hai Van pass is the coast road people mean when they say they are going to Huế. Allow something like one and a half to two hours, longer if you stop, longer in fog and heavy rain. The train is the calmer option if you do not want to ride it. There is a separate note on when Huế is worth the trip.
Ba Na Hills
This is a day trip into the hills west of the city, not a neighbourhood you live in. The cable car is the whole point, and it stops for weather. Read Ba Na Hills if you live here before you buy a ticket.