As far as I know, You will need to buy the extended license and also need to contact the author of the plugin. Someone correct me if I am wrong.
You should have the extended license BUT if you have an agreement and permission from the author then they may not require the license or want something else.
Out of interest if you do not know how to program and only understand design, HMTL and CSS how are you planning on creating/supporting a Wordpress theme?
I yes can make design html/css to wordpress, I can make themes only???
You can make whatever file type you want – PSD OR HTML/CSS OR WORDPRESS OR Blogger, Contrete 5, Muse, and certain other CMS platforms.
Thanksss SORRY, I bad understand you, I don’t speak english
You can make a file for sale her ein most platforms
The most common are PSD templates, Site (HTML/CSS/JS) templates or Wordpress themes.
Your design can be made in 1 or all of the different tools.
As a note – it is not your fault that English is not your main language but it is the community wide language and to create the necessary documentation and potentially to support your files you will need to have help from someone who will understand buyers questions