You can change the Quote Cart checkout template in Catalog Settings > Quote Cart.
Please find the Form Settings section on the Quote Cart settings screen and click the Edit Checkout fields button. Once you click it, you will see the checkout customizer.
One the bottom of the customizer screen, you will find the template switcher:
You can set the form type to
- labels top:
- labels left:
- labels & fields centered:
Each option has a different HTML output. The styling of the fields is still taken from your theme.
You can customize the quote form submit button.