I just open a route and I am starting to get in the market share what does that mean ? Does it mean I get more passengers now on the route ?
No, market share is a statistic of events past.
It just presents the percentage of PAX you carried in the total number of PAX travels to/from the airport. It doesn't mean anything. You may use that to see whether your are the leading airline in that airport, but it's not important. You don't know whether you get more PAX since it may also be other airline reduce PAX travel to that airport. When you opened new routes, you provided more seats from/to that airport and carried more PAX. Your market share should increase if other airlines didn't add more flights to the airport.
Also, I would add, that even if you increase market share and other airlines have reduced market share, that doe snot mean other airlines are carrying less passengers than they were before.
Basically it is the SHARE you have on the airport or route.
Definition of SHARE: a part or portion of a larger amount which is divided among a number of people, or to which a number of people contribute.