write trigger that when a country(custom field) of  account(standard object) is updated, the country(custom field) of contact(standard object) should be copied

Write trigger that country (custom field) field of account object  should get copied with the value of country(custom field) of contact object whenever a contact is created or account is updated

 

Write trigger that country (custom field) field of account object  should get copied with the value of country(custom field) of contact object whenever a contact is created or account is updated

 

Hello, 
I'm trying to create a trigger to update a field based on the value of another field. The field I'm trying to update is a picklist and the values I'm trying to update it to are active picklist values. There are various HS_Original_Source__c values that if they are populated, I want the standard leadsource field to have it's equivilant value. Ex. HS_Original_Source__c is ORGANIC SEARCH and would map to leadsource of Organic Search.
 

trigger LeadSourceTrigger on Opportunity (before update, before insert) {
 List<Opportunity> oppList = new List<Opportunity>();
    
    //Go through the updated records coming into the database and update their custom fields 
    //according to the updated lead source 
    for(Opportunity opp : Trigger.new)
    {
        if(opp.LeadSource == '' && opp.HS_Original_Source__c != '' && opp.HS_Original_Source__c != 'OFFLINE')
        {
          if(opp.HS_Original_Source__c == 'ORGANIC SEARCH')
          {
               opp.LeadSource = 'Organic Search';
               System.debug('organic search');
           }
           /*
              if(opp.HS_Original_Source__c == 'next value')
          {
               opp.LeadSource = 'next value';
               System.debug('next value');
           }
           
           
            */
          
          //Put each updated record in the list created
          oppList.add(opp);  
        }
        
 }
 }

Any help would be much appreciated.