You can't change the format for the creation date, it's not supported. For tags, you don't have to change anything in

dendron.yml

, they should be enabled already! You can create tags by writing

#my-tag

in your note, or adding it to the frontmatter of the note like:

...
created: 1234579900
tags: ["my-tag", "other-tag"]

Here's more on tags: https://wiki.dendron.so/notes/8bc9b3f1-8508-4d3a-a2de-be9f12ef1821/