Buy a quality car shampoo. I use Dodo Juice Wax Safe Shampoo, as its very mild but is pH neutral so its cleaning properties are good at the same time doesnt effect on the wax you had applied earlier on the car.
Wax : Dod Juice Light Fantastic is a great wax for White colors. Use that..
Fibre Cloth = Use Microfibre Wash Mit to wash the car, then a MicroFibre Drying or Meguiars Water Magnet cloth for drying the car.
You can get the stuff from @ahmad_yar at reasonable prices
Dodo Jucie Light Fantastic Small Pot (Enough for 8 - 9 wax sessions) for 1200/-Rs
Dodo Juice Wax Safe Shampoo (Enough for 50 or even more washes) for 1600/-Rs
Wash Mit for around 500/-Rs not sure if Ahmad bhai has got it,, Then the Water Magnet for approx 1200/-Rs