Hello, @Faisal,
1. Please copy and paste the below given CSS code to XStore >> Theme Settings >> Theme Custom CSS >> Global and check back to your site after removing the browser cache.
.content-product .button.add_to_cart_button {
font-size: 0 !important;
}
.content-product .quantity-wrapper {
display: none !important;
}
2. Actually that is coming from the Static Blocks and you have to edit and change the content as per your requirements: https://postimg.cc/BLPP1zKS
Regards 8Themes Team.