Hello,

1. To display the description tab you need to add content to the product then the description tab will be displayed.

2. The content of the About Brand tab is coming from the HTML Block that is added as the attribute description. You need to create HTML Blocks and add them as attribute description.

Screenshot for Clarification: https://ibb.co/K5dBRZk

You can read our detailed documentation in the following link:
https://xtemos.com/docs/woodmart/html-blocks-2/#cat_att_tag

Best Regards