LDAP setup is under Explore → Integrations.
how can I upgrade from this setup ? I have followed your guide. but here is no frappe user, no frappe-bench folder. So how will I update from this version future? how can I give bench update command and from where?
You can follow the bench wiki here.
Also after installing you should have a folder called frappe-bench in the current working directory, change to that directory and run bench commands.
A screen shot or error log would make it easy to help you.
If you ran install.py with no command line arguments you will have a frappe user on the server and everything will be in /home/frappe/frappe-bench.