An unexpected error occurred while inserting Opportunity records and we couldn't check your work. Make sure Opportunity records can be inserted in this org, and click "Check Challenge" again. If this continues, contact the Trailhead Help team.

@Pothani Vamshi

here are the steps:-

• First click setup then open object manager.
• Second click opportunity then open field dependencies.
• Third edit field dependencies and make sure every lost and won values are included then save it then check your challenge.

• please find the similar thread:
  • https://trailhead.salesforce.com/trailblazer-community/feed/0D54V00007WdiPLSAZ
  • https://trailhead.salesforce.com/trailblazer-community/feed/0D54V00007UpAE7SAN

 If you are still facing any errors, create a new playground and follow the steps I mentioned below. 

• https://trailhead.salesforce.com/trailblazer-community/feed/0D54V00007X7ETaSAN