how do I set up an apple account without giving out credit card details? the 'none' option is not there and I just want to download free app.
See the instructions in: https://support.apple.com/en-us/HT204034
If you follow the instructions in the link you will end up making a 2nd Apple ID from the one you already have. That isn't a good idea, having multiple Apple IDs. I'd buy a small iTunes Gift card and redeem it in lieu of a bank card.
You are not required to provide credit card information to create a new Apple ID.
In conjunction with opening an iTunes or Mac App Store account, millions would beg to differ with you.
How do I create an Apple account without credit card
