Drupal has robust ways for users to register.
User URLs
Users can log in at /user/login, and log out at /user/logout.
Register at /user/register and reset password at /user/password.
When you are logged in, /user will redirect to your user profie IE /user/1
Login Block
Place the login block anywhere you want - it will only show for anonymous users.
Admin Add User
Admins can add new users directly.
People > Add user
Registration Workflow
When a user registers, they are sent an email with a url to log into the site and set a password.
It's important that the site is able to send emails, so make sure to test this.
If emails are going to spam, look into other services to send them, which may have more authenticity to spam filters.
User Login Alias
The user alias is not case sensitive.
Either the alias or user email can be used to log in.
Manage Users
Add, block, or remove users. Add or remove roles.