If you would like to make your login page look different, you can do a template override and no need to redirect to a different page.
Find your templates folder and select the template you are using.
Create an html folder if you do not have one.
The component you wanna override is com_users.
If you have a look at /components/com_users/views
folder, you can see all the views that can be overriden in the template folder. The one we need now is in the login folder.
/components/com_users/views/login/tmpl
- there are default.php default_login.php and default_logout.php.
You have already created an html folder in your template, now you need to copy these files in the following location:
/templates/yourtemplate/html/com_users/login
That will result in having 3 files:
/templates/yourtemplate/html/com_users/login/default.php
/templates/yourtemplate/html/com_users/login/default_login.php
/templates/yourtemplate/html/com_users/login/default_logout.php
You do not need the tmpl folder.
You can edit the default_login.php to do the override.