You create and edit content in Weceem from the Repository view, which requires you to log in to the administration interface first.
Once you are in the correct content repository you can use the New Content action to create new content nodes, or click on the title text of any existing node to edit.
When creating new content the currently selected repository node will become the parent. You will be asked what kind of content you wish to create, and then be shown the content editor for that content type.
Different content types have different fields and capabilities, and the editor adapts accordingly. Most content types will have at least a Title and Status, an area for the main content, and the Extras, Metadata, Change history and Parents & Children sections.
In the editor you can Save and return to the repository or save and continue to keep your changes but carry on editing. You can also Preview your changes in a new window without saving them, if the content is able to be rendered in isolation (e.g. Templates and Widgets cannot themselves be previewed).