I received an audit notice; what happens in the audit?
I would pull the supporting documentation for all items on the return as step number one.
Consider having a professional represent you in this situation as step number two. It will reduce your stress and allow a professional to engage the auditor (you as much as you may try are not a tax professional) who is experienced with what auditors are looking for and can keep the audit from becoming personal.
This is a common perception that a mistake on an audited tax return leads to corporal punishment or worse. Mistakes are part of many filings (mostly inadvertent) and are dealt with as an “adjustment” to arrive at a final figure for taxation or refund. Typically an IRS or state representative, absent a pattern of deceit, and a large dollar amount of mistakes will often assume the best. The common perception that a mistake is sending you to jail is false.