How to edit checkout?

Question

WooCommerce

You need to create your own order form.
The difficulty is that you need not to deviate from the layout and layout that has already been done, and there are so many bells and whistles that you cannot implement this using standard methods. In this regard, I have several questions at once:

1. Is it possible to simply enter the necessary "name" and "type" fields in the frontend so that data is transferred from them?
2. Where is the handler for this form? I have compiled a template for checkout, but when I submit the form (even the one that is standard, I output it through hooks), nothing is sent to me. Judging by the action in the form itself, this data is sent to the same page. As a conclusion, there is no handler.
3. What is wpnonce? I understand that this is protection? Can I display the correct wpnonce, are there hooks, actions?