Editing Library Items in Templates

Your goal should be to get as far away from Dreamweaver dependant workflows as possible.  Instead, you're re-arranging deck chairs on the Titanic.  😥

See my other reply in your previous post.  It applies to this topic, too.

https://community.adobe.com/t5/dreamweaver-discussions/website-templates-for-dreamweaver-2021/m-p/15149059#M229970

Have you stopped to think about what you will do when DW is no longer available?  

CODE EDITORS:
-- Codespaces (free, browser-based) - https://github.com/features/codespaces
-- Notepad++ (free) - https://notepad-plus-plus.org/
-- Nova (Mac only, formerly called Coda) - https://nova.app/
-- Pinegrow - https://pinegrow.com/
-- Sublime Text - http://www.sublimetext.com/
-- Visual Studio Code (free) - https://code.visualstudio.com/
-- Wappler ~ Visual Web App Builder - https://wappler.io/
============
ONLINE SITE BUILDERS:
-- Squarespace - https://www.squarespace.com/
-- Webflow - https://webflow.com
-- Wix - https://www.wix.com/
-- WordPress (open source) - https://wordpress.org/

The term "template" can have various meanings in web development, leading to potential confusion. Here's a breakdown to clarify:

1. Marketplace Templates

Platforms like ThemeForest offer a vast array of templates designed to expedite website creation. These templates are not proprietary and typically utilize open technologies and libraries such as HTML, CSS, JavaScript, Bootstrap, Vue.js, React, among others. Once you've selected a template that aligns with your technological and aesthetic preferences, you can edit it using any development tool—be it Dreamweaver, Visual Studio Code, UltraEdit, etc.—without any compatibility issues.

2. Dreamweaver's Proprietary Templates

Adobe Dreamweaver employs the term "Templates" in a specific context. Since its early versions, Dreamweaver has featured an internal mechanism that allows users to create a master template (.dwt file) to generate and maintain child pages. This system is unique to Dreamweaver and differs from the general marketplace templates mentioned earlier. For more details, refer to Adobe's guide on creating Dreamweaver templates.

3. Dreamweaver's Starter Templates

To add to the complexity, Dreamweaver introduced Starter Templates a few years ago. These are pre-designed layouts intended to help users kickstart their projects. They are distinct from both the marketplace templates and Dreamweaver's .dwt files. More information is available on Adobe's website: Build from Website Templates.

4. Dreamweaver's Library Items

Furthermore, Dreamweaver offers Library Items (.lbi files), which, like .dwt files, are proprietary tools specific to Dreamweaver. They allow for the reuse of page elements across multiple documents. Learn more about them here: Using Library Items.

Recommendation

Given that Dreamweaver is currently in minimal maintenance mode, as noted by @BenPleysier , it's advisable to avoid basing new projects on proprietary tools like .dwt and .lbi files, which are not compatible with other development environments. However, if you're using non-proprietary templates, feel free to utilize them extensively.

On a personal note, I continue to maintain sites that rely on these proprietary tools, despite the limitations 😉 .

In Summary

While Dreamweaver's proprietary templates and library items offer certain conveniences within its ecosystem, they can lead to compatibility issues with other development tools. In contrast, non-proprietary templates from marketplaces like ThemeForest provide greater flexibility and are widely supported across various platforms. Therefore, for new projects, it's recommended to opt for non-proprietary templates to ensure broader compatibility and future-proofing.

To give you a quick answer, and add to what @Jon Fritz says, as soon as you create a library item, the folder will be created automatically.

This is a very broad question and is subject to the amount of coding knowledge that one has attained.

For me, I would have nothing to do with library items in Dreamweaver, they are very buggy. I would go into code view and make the adjustments there.

You need to ask program questions in the forum for the program you are using
To ask in the forum for your program please start at https://community.adobe.com/
Moving from Using the Community (which is about the forums) to the Dreamweaver forum