Very east to create Account score code Salesforce Apex

This is Salesforce Assignment which is need to done in Apex for my work.

Write automation that gives an Account a score in a custom object called “Account Score” related to the Account. On this, record a count of Contacts with a populated email address and a count of open Opportunities, and a field that adds together those counts. If the count is less than 5, the score should be Low. If the score is between 5 and 10, the score should be Medium. If the count is greater than 10, the score should be High. Perform these calculations asynchronously. For this assessment, do not leverage roll-up summaries.