Create a Case and Opportunity Related to an Account

// Retrieve the Account record for which you want to create related
// Cases and Opportunities

Account ram = [SELECT Id, Name FROM Account WHERE Name = 'Ram'];

// Create a related Case. Note that there is a more efficient way to
// instantiate the Case object than what's shown below. The steps shown
// below is the "long" but more familiar way for new developers.

Case ramCase = new Case();
ramCase.AccountId = ram.Id;  // Set the relationship to the Account
ramCase.Subject = 'Sales Cloud Best Practices';

insert ramCase;

// Create a related Opportunity. Depending on your org's configuration,
// you may need to specify values for other required fields.

Opportunity ramOpportunity = new Opportunity();
ramOpportunity.AccountId = ram.Id;  // Relate the relationship to the Account
ramOpportunity.Name = 'Sales Cloud Implementation';
ramOpportunity.StageName = 'Prospecting';
ramOpportunity.CloseDate = Date.today();

insert ramOpportunity;