Hello,
Some questions require more time to answer. Please, be patient. We’ll answer to all your questions step by step.
1) Don’t place/replace any file of the parent theme. If you need to improve anything use a child theme for these purposes. In other cases, you will lose your changes after the next theme update. Take that into account.
2) Copy archive-products.php file to your child theme and edit that if you want to display any information before the products instead of after.
Regards