Question: VS Code someone point me to an existing opened file, other times it create a new instance (of VS Code as well as the file).

Answer: 
By default, VS Code will open a new Editor with the desired file. If you'd like to instead reveal the already open Editor, set workbench.editor.revealIfOpen to true in your User Settings (CMD+k on OSX).

To be concrete, that means adding the following line:

```json
"workbench.editor.revealIfOpen": true,

```

**See Also**: [Visual studio Code - prevent same file opening twice](https://stackoverflow.com/a/43135102/2970867)
This worked for me:

```
  "window.openFilesInNewWindow": "off",
  "window.openFoldersInNewWindow": "off",
  "security.workspace.trust.untrustedFiles": "prompt"

```