You're entitled to request a free credit report from each of the agencies: Experian, TransUnion and Equifax, but some web sites offering a free credit report require payment of some kind.
Make sure you use Annual Credit Report.Com where you can access all three agencies once a year at no charge. Ignore any suggested additional services which incur a fee.
Suggestion: Rather than checking all three agencies at one time, check each of the agencies in four month increments so that you will be aware of any problems without waiting a year and will cover all three in a one year period.