in Umbraco I want to create a custom data type which represent a dynamic list of Entity which has a content in "RichTextBox" and a primary image.
I want use this dataType to create a page with a list of related topic witch are not a independent article and are only related to main Article.
how can I create this DataType? is there any solution with combination with Macroes and datatype in Umbraco?
There is a package named Archetype which, if I understand you correctly, will provide you with what you need (a dynamic list of custom datatypes): https://our.umbraco.org/projects/backoffice-extensions/archetype/