I am not sure I understand the question. An internal auditor (1st party) absolutely does not need to have certification body (3rd party) audit experience to do internal audits, unless the organization specifies in its own requirements.
People who have had external training then train internal auditors internally all the time. Internal auditor "certification" is done as per the organization's training structure, very often to include performing at least one audit under the supervision of the training and/or other person, as is defined in the qualification process.