Test class isn't quite good enough - how do I beef it up?

public with sharing class QualOpController
{
public List <Opportunity> Opty {get;set;}
public list<String> campaigns {get;set;}
public void load() 
{
  campaigns= new List<String>();
  Opty = [Select id, name, Company_Name__c, Vertical__c, Weeks_Live__c, Days_Since_Last_Modified__c, Contract_SENT__c, NextStep, LeadSource, Probability, Spend_Last_Week__c, Spend_Last_30_Days__c, Owner_Name__c, Revenue_All_Time__c from Opportunity WHERE StageName = 'Qualified' ORDER BY Probability DESC]; 
  Set<String> campaignSet = new Set<String>();
  for (Opportunity j : Opty)
      campaignSet.add(j.Vertical__c);
      for (String campaign : campaignSet) 
      {
            campaigns.add(campaign);
      }
      campaigns.sort();
    }
}

@isTest(seeAllData = false)
public class QualOpControllerTest{
    // Unit test Method
    static testmethod void UnitTest() {
        //Create your opportunity record with required field
        //Opportunity j = new Opportunity(StageName = 'Qualified');
        //insert j;
        test.startTest();
            QualOpControllerTest qo = new QualOpControllerTest();
        test.stopTest();
    }   
}