How to Enable User Registration in WordPress without plugins.
WordPress out of the box comes with user registrations set to default to off, you can change.
Go to Settings >> General page in your WordPress admin area in go down to the Membership section and check the box next to Anyone can register.
New User Default Role.
Roles in WordPress come with sets of permissions and capabilities, what a user can and cannot do on the website. They can be set Under Settings >> General scroll down to Membership and Tick that box.
The default user role is subscriber, which you can change to other user role from Subscriber – Contributor – Author – Editor or Administrator. For example, if you want users to write posts on your website then you can change the default user role to Contributor or Author depending on your own levels of trust of that user.
WordPress plugins can add User Roles for example woocommerce online shoping adds – Shop Manager and Customer roles.