I am creating a web application, but I am not a designer. So I'm basing myself on a lightweight CSS framework to provide the basic style and structure of different elements of the user interface. However, I often have trouble structuring the web application to provide a good UX.
I've googled "ux web application design" (and "user interface design"), but most of the results speak to the design of a "web site" and not to A "web application". For example, the main objective seems to be the design principles, for example: color / contrast, visual hierarchy, spacing, etc. What I need, for example, is the general layout of the applications, the star pattern, the navigation, the sidebars / menus, the relationship between the conceptual / data model and the pages / screens, role-based features, save details vs. lists / tables, page sections / layout, maps, page actions, form design for easy page manipulation vs. complex data entry (multi-step wizards ), etc.
Where can I find such a tutorial or guide? I am willing to pay for an online course if there is one.