You can enter the city of Vientiane by reaching to this place at Wattay Airport located 4 K.m. outside the city. There are railway options available to be considered in case you want to travel to this city through Bangkok .
From Indian there are numerous flight that land directly at the Wattay Airport. Some of the companies which offer flight to and back from Vientianne include Thai Airlines, China Eastern Airlines as well as the Vietnam airlines
As mentioned before you can enter this city through the international flights which would help you land on the Wattay Airport located 4 k.m. North of the city.
You can reach to the Wattay airport and from there you can find tons of cabs which would take you to your booked hotels.
You can reach here through the medium of train by reaching to Bangkok and then taking a trail from there which would leave you near this city from where you can hire shuttle services.
You can visit this place by roads through the common Friendship bridge shared by the country of Thailand. There are frequent shuttle services to this location. You arenêt allowed to cross this bridge either on cycle or on foot. Other ways of entering this place through bus is by taking one from Vietnam or from Cambodia each of which takes a minium of 20 hours to reach this city.
There isn't any route to Vientianne by Sea.
You would be able to travel comfortably through this city as there isn't much traffic to be seen on the roads. In case you want to known the directions then try asking people around about the nearest locations to those places. Also make sure that in this city people pronouce "R" as "L". You would be able to find in some taxis which would take you to the locations that you like and are ususally the best means of communtating. However you can even travel by tuk-tuk which is something of a auto rikshaw, or you can choose bus services from travelling within districts.