List of user

less /etc/passwd 
or
cat /etc/passwd

If any process is running in your desired user I wanto delete you can kill them List of all running process

ps aux | grep odoo14

Kill a running process.

sudo kill -9 port
Example:
sudo kill -9 4998

After killing all the process delete the user

sudo deluser odoo14

Now delete all the related folder

sudo rm -R /odoo14
sudo rm /etc/odoo14-server.conf
sudo rm -R  /var/log/odoo14/

For installing odoo you can follow https://github.com/Yenthe666/InstallScript#readme this tutorial. This is one of the best way to install odoo in ubuntu