I moved this to have its own question to get better and quicker answers. See How to post a question on this MSOffice forum.
Here is a link to the previous question thread: https://www.msofficeforums.com/word/...-when-tab.html


First, I strongly recommend that you read each of these small tutorials: Basic concepts of Microsoft Word: An introduction by Shauna Kelly, MVP, especially...

• 2.1 Why you should not press Enter at the end of every line
• 2.2 Why you should press Enter only once to end a paragraph
• 3. Using Styles to Format Text

You can have single spacing in general or for lists.

Word's defaults are not for double-spacing or 1.5 spacing. The default for line spacing is generally 1.16 which, in my opinion enhances readability. The default for spacing between paragraphs is 6 points after. There is a checkbox to not add space between paragraphs of the same style. The paragraph spacing for before and after are what shows up when you press Enter.

This can all be done in a single document, in a custom document template, or for all new documents.