I made My card with HTML CSS JS
It's made with html only
I don't think this will do anything and it's a separate js file so you don't need to add
You don't need as it is a separate file if you are using it in the index.html file you can add internal styling
And you shouldn't remove the basic html structure, you can remove it but then you'll have to link the css and js or use internal styling and internal script.
I don't know about js but this wouldn't link the stylesheet to the html file.