It is probably worth putting some advise here about explaining to your boss that you don’t know what you are doing and doing a risk assessment about following advise from internet experts on a community forum.
Hopefully this is not a major system and any further mistakes are not a Resume Generating Event.
From your post it is difficult to tell what state you have managed to get to. There is the possibility you have upgraded the mongod binary as well and are a service restart or server reboot away from downtime(3.6 to 4.4 direct upgrade won’t start)
Please provide:
- What OS your installation is on.
- The server and shell versions output from mongo when you connect.
- What steps you took on your “upgrade”.
As a note the 3.6 version went End of Life April 2021. So you should be upgrading, but also be following the upgrade path and procedures outlined in the documentation.