Why is my app in the app store is all need to purchase with visa and such other things? As a example i wanted to update the clash of clan apps, but it keep saying that i have to do a billing thing. Please help me.

Apple wants you to verify your billing method because Clash of Clan game is an in app purchase. Meaning the game is free but the gems are not.

Verify payment method > iTunes Store: Changing account information

There's also a link to contact iTunes Support at that link if you need it.

This is incorrect. "There is a billing problem with a previous purchase. Please update you payment method. " means you have made a purchase and iTunes/Apple hasn't received the finds for it yet. hence the "There is a billing problem with a previous purchase. Please update you payment method. ". This means you would need to either use an iTunes gift card to pay it off or another debit or credit card that is currently on the account.

When it is asking to verify the information- it says "please verify..."