Hello, @TFS,
1. If you are using the Single Product Page Builder functionality on your site, then you have to go to XStore >> Theme Settings >> WooCommerce >> Single Product Builder >> Tabs and turn ON the Custom Tab 1 and 2 and then add the content in them as per your requirements.
https://postimg.cc/7fmbw4Bt
https://postimg.cc/PL8WFyW4
2. If you are using the prebuilt/default layout for the single product page then you have to go to XStore >> Theme Settings >> WooCommerce >> Single Product Page >> Tabs and set the Custom Tab Content from there as per your requirements.
And VENDOR & QUESTIONS/ANSWERS Tabs are coming from the MultiVendor plugin, so if you are not using the Multivendor plugin on your site then those tabs will not appear.
Regards 8Themes Team.