I'm creating a forum for a school and I want to give everyone username access to the forum and a test password so when they log in they are asked to add their password, mail and birth date how could I do that?
You could create each user manually in your Admin Control Panel.
Admin Control Panel >> Users & Groups >> Users >> Create New User
After you've supplied them with their credentials they can then login and change the above information in their User Control Panel.
Better sluation is use fb contact plugin.
User register by one click using fb account information and new password will bhi automatically pm those persons how registered by using our fb account.