You can reach to the Hanoi city located in this country by taking numerous direct flight from India. From their you can get bus or train which would drop you off in the Sapa region. Flights such as Bangkok Airways and Air India would serve you to the Hanoi destination.
There isnêt any direct route to this place through air. You can reach the aiport located in Hanoi and from there you can either take a bus or train which would comfortably leave you in city in about 9 hours.
You can always rent a car or taxi from Lao Cai or Hanoi but it would be much costly then you travelling throught bus or train.
This city is known to have Lao Cai Railway Station which can be reached by taking a train from Hanoi. This train would take an approximate 9 hours to get to the city of Sapa.
You can also take a sleeper bus from the city of Hanoi or from Lao Cai to Sapa which would allow you to reach this place in around 10-11 hours.
No known methods of travelling to this bay by sea are known.
You can easily move around this place on foot and it is very unlikely that you would require any help or guidance.