Good morning, Dear Srs.

Please request your help for the following situation.
To finish configuring the site and delivering it to my client, I just need to resolve these 3 issues related to the same situation or problem.

As you can see in the attached photo (help please), I need help with what I marked the following numbering:
1 – I need to know in which file I can change the label on the “add to cart” button for something else.
2 – How can I set the price / in this case the price so that the respective percentage of discount appears depending on the price.
3 – How can I change the image to one I like or about the featured product? I tried it in Admin >> Appearance >> Widgets >> Sidebar Menu # 2 (where it is located on my website) >> widget image, and when I change the photo there, it does not update on my home page. And I can’t find the place to set the price / percentage of the product there.

Thank you so much for your help, I look forward to it.
Compliments
Ricardo