Cant use Iphone, have no software

The game you want to download is free and doesn't cost anything. But to download the app, you need to have a valid payment tied to your Apple Account, because it, like most free apps offer "In-App Purchases." It doesn't mean you ever need to make a purchase in-app, but it does require you to have a payment method. Without one, you can't download any app, which has in-app purchases.

Here is a link you can use to see what payment methods you can use with your Apple Account --> Payment methods that you can use with your Apple ID - Apple Support

Hello,

there are free apps in App Store too. If the price isn't listed near the name or icon of the app (look at attached pictures) - this is a free app. For free apps, the “buy” dialog means you register this particular app to your Apple ID account, which enables downloading it.

The iPhone comes with all basic software needed to use it as a phone, texting device and email. There are over a million 3rd party apps; some of them are free, and some of them must be paid for.

No worries. Everyone was a newbie at some point! ;-)