I don’t want to have Apple Card anymore because I don’t trust anybody and I wanna know how to pay my existing balance and then how would I pay for iCloud is there anyway I can put my credit card in to pay for that

For the payment part on your iPhone, go into the Wallet app and you will see the Apple Card at the top. You can choose it and make a payment under the payment option. If you do not have an iPhone or access to one, use https://card.apple.com

You may have to add the credit card you want to use before it will allow you to remove the Apple Card. On your iPhone, go to Settings and click your name at the top. Chose "Payment & Shipping" and then click "Add Payment Method" to put in the new card info. On a Mac, go to the App Store and click on your name in the bottom right corner. Click on "View Information" on the top of the window and it will ask you for your iCloud password. The payment information is the third list down and you can click on "manage payments" to add your card there.

You only have to add the card using either method, not both.

FWIW, using ApplePay is arguably the most secure means of using ANY credit card.

Swiping a physical mag strip is the least secure.

An EMV chip transaction is somewhere in-between.