Hello,
I saw the screenshots you attached.
1) Sorry but there is no option available to add subtitles as you mentioned.
2) You can configure the social buttons on the website from Theme Settings >> Social Profiles.
Screenshot for Clarification: https://ibb.co/2s7FhBB
3) The description tab content is displayed that you added in the product by editing the product.
Screenshot for Clarification: https://prnt.sc/xsrjr9
If you are trying to ask anything else then please provide with some relevant screenshots of the specific area to check it myself and help you out accordingly.
4) You can find the available options for the single product page under Theme Settings >> Product Page.
You can read our detailed documentation in the following link:
https://xtemos.com/docs/woodmart/product-page-options/
Best Regards.