Hello Sifu,

I am building a website and would like to use a registration page as a marketing tool.

By that I mean my promoter will have an iPad in hand, they can help users to register.
However if they use the existing registration page, after registration, it will automatically log in the user, which will waste some time for the promoter to logout and go to registration page again.

This auto log in is useful for self registration with I don't want to disable, but I am thinking if there is a plugin that I can install to create another registration page where people can register and it won't auto login.

Thanks,
Joel

Easy, use user registration form. Example:
https://fluentforms.com/create-user-registration-form/