Hi there @bialas6666!
Don here from Shopify. :)
Unless your store is on Shopify Plus, it would not be possible to edit the checkout area in this way as the checkout is code-locked for security reasons.
That said, there are some style elements of the checkout area you can customise, as laid out here.
Have a look at the options that are available to you for editing this and see what you want to put in place for your store.
Are you still getting set up to sell online and have you been selling elsewhere in the past?