Please show the employee first names and ids of employees who serve at least 10 customers.
SELECT T1.FirstName ,  T1.SupportRepId FROM CUSTOMER AS T1 JOIN EMPLOYEE AS T2 ON T1.SupportRepId  =  T2.EmployeeId GROUP BY T1.SupportRepId HAVING COUNT(*)  >=  10
Lütfen en az 10 müşteriye hizmet veren çalışanların adlarını ve kimliklerini gösterin.