1. You can manage users in Drupal by going to Administer -> User Management.
2. You will have five sections here, here is a short explanation of each:
Access Rules – from here you can define the access rules for your Drupal installation. You can disallow users, emails, and IP addresses.
Permissions – in this section you can see which modules will be available to your site’s visitors.
Roles – Here you can add rules for anonymous and authenticated users. You can assign roles such as administrators, moderators, etc.
User Settings – this section allows you to configure the registration settings for new users and allow an email to be sent to notify of a new registration and password recovery.
Users – this will show a list of all of your site’s current users. You can add new users and block existing ones as well from this section.