where creating nodes (node/add/content-type) bellow body box there are some options related to comments, author, menu and ..
How can I hide those options?
You need to create a module and implement hook_form_alter.
Then, in the $form array, unset the array index(es) containing the parts you don't want your users to see and configure.
ps: I advice you do the above by permissions. So, those array indexes are unset for specific roles not all roles which would include user#1