Hello and welcome to our forums!

Make sure you first download the also free CB Primer book and study it along with all the resources it directs you to.

This will help you understand the guideline answers provided below.

epsilongr wrote: 1)How can i send to a new member an id (perhaps the user id from joomla)?For example
When a new member join Community builder the registration mail seems like " Hello John Doe,you just registered to our site bla bla bla and your personal member id is 111222333444
and i also want to see somewhere this personal ids

Your language.php files of your relevant CB Language plugins (see Primer for details and resources) have the language strings responsible for the welcoming message.

They look something like:

'YOUR_REGISTRATION_IS_APPROVED_SUBJECT' => 'New User Details',
'YOUR_REGISTRATION_IS_APPROVED_MESSAGE' => "Welcome [NAME],\r\nYour application has been approved by our administration team.\r\nYour account with the following details:\r\n[DETAILS]\r\nhas been activated.\r\nWe welcome you to our online community and trust that together\r\nwe will grow.\r\nEnjoy the experience!\r\nKind Regards,\r\nWebsite Administration Team",

You should be able to edit these and add CB Field substitutions (see Tutorials section for details) to add the user_id field.

2)When someone change his profile picture i have an email that "A member changed his profile picture but i havent a name or id or whatever and at the administrator there is not a sign of who changed his/her picture so i can check and approve the changes.I cant search one by one who he/she is.

Thanks in advance

CB Primer and Getting started resources explain the usage of the CB Workflows module which needs to be used to address your issue.