Creating New Theme

New user. I have Beaver Builder and Beaver Themer.

I wanted to build a new theme. Clicked on ‘New’ and selected ‘Themes Layout’.

The Header option was ‘Header (Unsupported)’. I continued and sure enough, I can’t edit the header.

What am I missing?

Question: When creating a ‘New Theme’, does it inherit any settings from the current active theme?