money for short term usa visit

[pal2141]

Hello, i will be going to USA for short 3 month stay on b1/b2 -MUMBAI TO USA

I wanted to know how much cash can i take through airport or how much would be sufficient for just travel purpose and were can i get USD dollars currency in Mumbai?

Also during my stay, using my debit/credit card would be better or should i take a travel card? Any other financial sugestion are also welcome.This will be my first visit. Thank you