Do we need to click on Archive and only then it goes to Archive folder?
Yes, only when you click on archive can the template enter the archive folder.

After archive still can we edit it or must move to other folder first?  Is it impact the Journey? In what circumstances I need to archive it? What is the purpose to archive template ?
- You can archive templates from the panel to move unwanted templates to a new folder - archive.
- Archived templates cannot be edited, but can be restored at any moment should you choose to.
- Once a template is archived, it will not appear in the drop down of your journeys.
- Once you archive a template which is currently being consumed in Journeys, it will not have any user impact and will work as is.