Help : Editing fields for Checkout Page and Using

[FrancoPG]

Hello everyone,

I make this post to get help on the subject of the checkout page, I have several problems:

1 - I would like to know how the order is established for the different order steps (example put the Address step before the personal information step).
I know it is directed by the "checkout-step.tpl" page but how the personal information page is before the address page and not the other way around.
2 - I would really like to understand the architecture of Prestashop to make my modifications, such as taking a field from the address tab to the personal information tab.
3 - Change the HTML structure of the checkout page because if I change the css, it changes the css of all the pages or I want to modify only one page ( because I have a figma model to respect ).

I ask you all this because in addition to wanting to make my project a success, I have the objective of making a guide for those who want to, I have already started but there is a lot of information and understanding missing.

Thank you all in advance.

Edited January 23, 2023 by FrancoPG (see edit history)