Hello,

1) If you want to keep title which is in the red box and delete the box with the green border then use the below css code in Theme Options >> Custom CSS:

h1.product_title.entry-title{
display:none;
}

Screenshot: https://jmp.sh/khdHSPt

In case if you want to delete the red box and keeps the green box title then use the below css in Theme Options >> Custom Css:

nav.woocommerce-breadcrumb{
display:none;
}

2) The template file of the product display page is:
wp-content\themes\woodmart\woocommerce>> single-product.php

Best Regards