Lead Developer
Hi there,
The style.css and functions.php files in your child theme are meant to start empty, then you add to them. No need to copy the parent styles or functions over.
However, every other file that doesn’t exist in the blank child theme needs to be copied from the parent into the child theme if you wish to edit it. If you edit a file in the parent theme, your edits will be removed when you update the theme. Copying the file from the parent theme and adding it to the child theme allows you to make changes which won’t be touched when you update.
Not too sure what you mean by the second part, but if you have styles that are running into widgets, it’s most likely caused by a unclosed HTML element. For example, for every <div>, you need a </div>. For every <span>, you need a </span>. If one of these elements opens but doesn’t close, the styles of that element will run wild into other elements.
Hope this helps 🙂