I want to write a Apex code and debug. I logged-in Salesforce and inside Salesforce Developer Console, Apex Class and Apex Trigger is invisible. I am not able to click that.
Path : Salesforce Developer Console > File > New > Apex Class / Apex Trigger
you need create a new account in salesforce to developers, the account which you uses is a production account, the production accounts don´t have permissions to create a new Apex class and Triggers, i let the link to signup developer account in salesforce bellow. here I hope this comment help you.