Hashtags and notes

I am just beginning with ZettleKasten.

I am trying to figure out how a note can be divided into individual notes.
I tried the refraction plugin, but nothing seemed to happen.

I also read somewhere the — is code for the beginning of a page. So, a divider between notes that may be written on one note??

The problem is not only technical. I hope I am not totally confusing. Or confused.

Here is what I am understanding:
Space # no_space makes a tag
Space # Space is a first level header (H1).
Headers and what they contain, I think are not “atomic” notes.
Some people seem to be using Header 2 (H2) and Header (H3) for different levels of abstraction that could be placed at he beginning of a note. Usually, I think of H1 above H2. It is more abstract. In normal writing, I do not write H2 without an H1 above it. In the ZettleKasten context that seems to be unimportant. H1 might be described in a MOC and further defined in another linked note. So, a note could start with H3 with the hope that the full context will be defined later or perhaps it already exists. Is that correct?

When I am first writing about a topic, I feel more comfortable leaving ideas together providing context. At least as I am thinking about the idea the particular context is important. When a part of a longer piece of writing can be boiled down into a sentence that could be used in many setting, that is a kind of happening. It does not happen with everything I write.

Using # + space + text creates an H1 element (# Header). Using # with no space creates a tag (#tag). You don’t need a space before # to make these features work.

Obsidian’s syntax is mix of Common Mark and GitHub flavored markdown. For a basic overview of formatting in Obsidian, see this link:
https://help.obsidian.md/How+to/Format+your+notes

“Atomic” notes in the Zettelkasten are individual notes. I have not heard of people using H3 for different levels of abstraction before. I would love to learn where you heard about it. I believe using different headers is for formatting purposes only. An example of this could be turning a .md file into a PDF. H1 would be the largest header and H6 would be the smallest. You can see what your file would look like rendered by going into “edit” mode. There are no “rules” for using H1 before H2, but it is common practice to use headers sequentially (Markdown formatting was based on HTML, where it is a “best practice” to use H1 before H2 and so forth).

You can create new notes by making new files. It is possible to link or embed notes, headers, or blocks. See these two links:
https://help.obsidian.md/How+to/Internal+link
https://help.obsidian.md/How+to/Embed+files