If you try to join Fortnite experiences and are unable to because it says "This experience is locked. Your parent or guardian needs to unlock it". This is because your parent or guardian has restricted what you can access on your account based on the rating of the game or event.
Once you select Unlock, your parent or guardian will need to enter their Parental PIN to allow you access to join that event or play that game. Parents who have forgotten their PIN can reset it by following our How do I reset my PIN for Parental Controls on my Epic Games Account?
Parents and guardians can adjust what is restricted in the Parental Controls settings on the account. For more information on Parental Controls, please look at our Parental Controls documentation.