how can I set "disabled user" as default configuration to any new user which register on, then send to any administrator an email saying "new user!!" and the administrator could anable the new user and send to him an email to let him know was approved
You will have to customize the register function.
To do so, you will have to use the extensions
folder.
See the documentation here: https://strapi.io/documentation/3.0.0-beta.x/concepts/concepts.html#extensions
Here is the register function you will have to update: https://github.com/strapi/strapi/blob/master/packages/strapi-plugin-users-permissions/controllers/Auth.js#L358
You will have to create ./extensions/users-permissions/controllers/Auth.js
file that contains a module.exports with only the register
function inside. Copy the plugin's one and paste it in the extension file we just created.
Then in you extend register function, you will have to update the params
object and set the blocked
key to true.
Just after this line https://github.com/strapi/strapi/blob/master/packages/strapi-plugin-users-permissions/controllers/Auth.js#L378.
Then if you want to send an email, you can use the email plugin that provides you a way to send emails.
Here is the example of how we send confirmation email: https://github.com/strapi/strapi/blob/master/packages/strapi-plugin-users-permissions/controllers/Auth.js#L508
Copy this line and update values to send an email to yourself with the content you want.