drupal 7 remove logon & password for anonymouse users
Go to admin/structure/block and look for the user login block set Region dropdown to none. If you are using the default Drupal theme, it would be under sidebar first category

UPDATE

but users can still create new accounts from /user page. To disable this, go to

configuration -> people -> account settings -> registration and cancellation and set "Who can register accounts?" -> "Administrators only".