How to add multiple individual in civicrm profile fields section in civicrm contribution page?
Unfortunately this cannot be achieved with CiviCRM profiles.
CiviCRM only offers an option to sign up as an individual or on behalf of an organisation.
A household cannot be linked via a contribution page.

You best option with WordPress would be to attempt building a form using CiviCRM caldera forms - https://github.com/mecachisenros/caldera-forms-civicrm