St malo is a city in the north of Brittany, France. The easiest way to get there for international travellers is to pick a flight to one of the following city:
From Dinard airport, the easiest way to get to Sain Malo is to book a cab (24 minutes drive).
From Rennes, there are numereous train from Rennes to Saint Malo (70km).
From Paris, flights are available to Rennes, or high speed train (1h25). Note that some trains are direct from Paris to Saint Malo. Check out https://www.oui.sncf/
More info on the St Malo Travel Guide