Train pass for 1.5 days

Do you really need to use public transport? The city centre is compact and walking is the best way of enjoying it all. It very much depends on where your hotel is situated.

My hotel is Hampton Hilton at the airport.

Please suggest if GVB pass works from there if not then suggest a good hotel/apartment under 100 Euro from where i can travel to central or a 120 euro hotel near dam square

Check in date is 15 Feb-19 evening
Check out date is 17-Feb-19 morning
2 adults and 1 9 year old kid

Regards
Ranjan

Have a search on Booking.com for a reasonably priced hotel in Amsterdam itself.
Effectively you have one evening and one full day in Amsterdam. If staying near the airport seems the best option, you need two return trips from your hotel. The best way is to take the train from Hoofddorp, which is a few minutes' walk (see this map). These train runs every 10 minutes or so to Amsterdam Centraal, while the hotel's shuttle service doesn't look to run very frequently.
Hoofddorp is not covered by the Amsterdam travel ticket nor by the GVB pass (which is only for metro, tram and bus within Amsterdam itself). A return ticket costs you EUR 10,60 and your child can travel on a so-called Rail Runner for EUR 2,50. Hoofddorp is a unmanned station. You need the ticket machine. Make sure you have a working bank card. If in doubt, you can buy your tickets at Schiphol airport, which has a manned ticket window.

"My hotel is Hampton Hilton at the airport." - sorry Ranjan, but it isn't at the airport.
That hotel is in Hoofddorp, which is a small town near the airport.
I would not call that location convenient for either the airport or Amsterdam. You need a shuttle or a taxi to get to or from the airport. They provide a shuttle because it isn't at the airport or in Amsterdam, if it was you wouldn't need a shuttle.
The good news is that it is within walking distance of Hoofddorp station, so you can get a train to Amsterdam.

If it is not too late, I suggest you change to a hotel in Amsterdam. Schiphol airport to Amsterdam is easy by train.

You can always purchase your train/bus tickets as you go.
The pass may cost more depending on how much you ride.
Regarding your hotel, consider to changing to one inside the airport if this is helpful to you There is a Sheraton and also a Hilton, both adjacent to the airport.