Can anyone tell me approximately how much money i need for each currency?

As You will be on school tour, mostly You don't need any currency with You. I suggest to take Your credit card, as it's more cheaper to take out money from an ATM, as to convert it in an exchange office. Anyway, do not take more then 10.000 HUF with You (approximately 40 EUR/50 USD) as in the usual places You can use Your credit cards, which is far cheaper than use the local currencies.