I tried to re-download and it’s asking for viewing billing information when the game is free

1.

You can re-download / download free apps, but you may need to have a payment method on file, even if the app you want tre-download / download is free. 

As long as you onlyre-download / download free apps, it costs nothing.

Then your payment method remains intact.

If you are going to re-download / download a free app, there is a possibility to purchase the 'better' version, for example from a free version to pro version.

But that is not mandatory.

Use your Apple Account balance as default payment, then it is up to you whether you use it or not.

Free apps has also In-app pruchase.

Your payment method is actually a kind of deposit, if you buy something, it will be charged.

2.

If you don't have a credit card or don't want to use a credit card, you can also use your Apple Account balance as payment method.

See -> How to redeem your Apple Gift Card or App Store & iTunes gift card

How to redeem your Apple Gift Card or App Store & iTunes gift card – Apple Support (UK)

When redeeming a gift card, the amount will be credited to your (1) Apple Account balance and (2) you need to set your Apple Account balance as your default payment.

(1)

See -> Check your Apple Account balance

Check your Apple Account balance – Apple Support (UK)

(2)

See -> Add a payment method to your Apple ID

Add a payment method to your Apple ID – Apple Support (UK)

If you update your payment method or add funds to your Apple Account balance, It would take about 1 to 3 business days in order to process.

If you're still unable to update your payment method, Contact Apple Support.

See also -> App Store & iTunes gift card -> Apple Gift Card - Apple (UK)

• Add money to your Apple Account balance anytime, no gift card needed.

Click here for more support and assistance.