Tahiti is a pretty exclusive place and resort and is very hard to get to and there's only so many flights that take off to Tahiti so you have to book in advance enough to get the flight to Tahiti and it's pretty expensive.
To be able to fly to Tahiti you must first fly to Papeete on the big island of Tahiti which is a 7 1/2 hour flight from Los Angeles California.
The Airport in Los Angeles California is the nearest International Airport that can get you to Tahiti.