Hi All ,
This code is wrking perfectly and i have completed the challenge
1) Campaingnlistctroller.js:
({
    
    doInit: function(component, event, helper){
        
        var action=component.get("c.getItems");
        action.setCallback(this,function(response){
            var state=response.getState();
            if(state==="SUCCESS"){
                component.set("v.items",response.getReturnValue());
                
            }
            else{
                console.log("Failed with state: " + state);
            }
        });
        $A.enqueueAction(action);
    
},
    handleAddItem: function(component, event, helper){
      var itemToSave=event.getParam("item");
      
        var action=component.get("c.saveItem");
        action.setParams({"item":itemToSave});
        
        action.setCallback(this,function(response){
            
            var state=response.getState();
            if(state==='SUCCESS'){
                var items=component.get("v.items");
                items.push(response.getReturnValue());
                component.set("v.items",items);
            }
        });
        $A.enqueueAction(action);
}
    
})


2)campaignlistcmp:
<aura:component controller="CampingListController">
    <aura:attribute name="items" type="Camping_Item__c[]" />
    
    <aura:handler name="init" action="{!c.doInit}" value="{!this}"/>
    <aura:handler name="addItem" event="c:addItemEvent" action="{!c.handleAddItem}"/>
    
        
    <lightning:layout >
        <lightning:layoutItem padding="around-small" size="6">
            <c:campingListForm/>
        </lightning:layoutItem>
    </lightning:layout>
    
    <lightning:card title="Camping Items">
        <p class="slds-p-horizontal--small">
            <aura:iteration items="{!v.items}" var="item">
                <c:campingListItem item="{!item}" />
            </aura:iteration>
        </p>
    </lightning:card>
</aura:component>

campaignlisthelper:
({
    createItem : function(component,event,item) {
        console.log('step6');
        var action=component.get("c.saveItem");
        action.setParams({
            "item": item
        });
        action.setCallback(this,function(response){
            var state=response.getState();
            if(state=="SUCCESS"){
                console.log('step7');
                var items=component.get("v.items");
                items.push(response.getReturnValue());
                component.set("v.items",items);
            }
            else{
                console.log('State Returned '+state);
            }
        });
        $A.enqueueAction(action);
    }
})

3)Campaignlistformcmp:
<aura:component >
    <aura:attribute name="newItem" type="Camping_Item__c" default= "{'sobjectType':'Camping_Item__c',
                                                                    'Name':'',
                                                                    'Packed__c':false,
                                                                    'Quantity__c':0,
                                                                    'Price__c':0
                                                                    }"/>
    <aura:registerEvent name="addItem" type="c:addItemEvent"/>
    
    <form>
        <lightning:input aura:id="itemform" label="Camping Name" value="{!v.newItem.Name}" messageWhenValueMissing="Camping Name cannot be blank" required="true"/>
        <lightning:input aura:id="itemform" type="number" label="Quantity" min="1" value="{!v.newItem.Quantity__c}" messageWhenRangeUnderflow="Enter minimum 1 Quantity" required="true" />
        <lightning:input aura:id="itemform" type="itemform" label="Price" formatter="currency" value="{!v.newItem.Price__c}" min="0.1" step="0.01" messageWhenRangeUnderflow="Enter an amount that's at least $0.10."  required="true"/>
        <lightning:input aura:id="itemform" type="checkbox" label="Packed?" checked="{!v.newItem.Packed__c}" />
        <lightning:input type="date" label="Date"/>
        <lightning:button label="Create Camping" class="slds-m-top--medium"
                              variant="brand"
                              onclick="{!c.clickCreateItem}"/>
    </form>
</aura:component>


4)Campaingnlistfomrcontroller:js
({
    clickCreateItem: function(component, event, helper) {
        console.log('step1');
        var validItem = component.find('itemform').reduce(function (validSoFar, inputCmp) {

            // Displays error messages for invalid fields

           inputCmp.showHelpMessageIfInvalid();
           return validSoFar && inputCmp.get('v.validity').valid;

        }, true);


        if(validItem){
            console.log('step2');
            var item = component.get("v.newItem");
            var newItem = JSON.parse(JSON.stringify(item));
            console.log('step3');
            //var items=component.get("v.items");
            console.log('step4');
            //items.push(newItem);
            //component.set("v.items", items);
            
           
         helper.createItem(component,event,newItem);
             
        }
    }
})

5)Campaignlistformhelper:
({
    createItem : function(component,event,item) {
         
        var saveEvent=component.getEvent("addItem");
        saveEvent.setParams({"item":item});
        saveEvent.fire();
        
         component.set("v.newItem",{'sobjectType':'Camping_Item__c',
                                                                    'Name':'',
                                                                    'Packed__c':false,
                                                                    'Quantity__c':0,
                                                                    'Price__c':0
                                                                    } );
    }
})

6)CampingListController:
public with sharing class CampingListController {
    @AuraEnabled
    public static List<Camping_Item__c> getItems() {
       return [SELECT Id, Name, Price__c, Quantity__c, Packed__c FROM Camping_Item__c];
   }
   
    @AuraEnabled
   public static Camping_Item__c saveItem(Camping_Item__c item) {
     upsert item;
      return item;
 }
}

7)addItemEvent:
<aura:event type="COMPONENT">
    <aura:attribute name="item" type="Camping_Item__c"/>
</aura:event>

8)CampaignListitemcmp:
<aura:component >
    <aura:attribute name="item" type="Camping_Item__c" required="true" />
    
   <p>Name:
       <ui:outputText value="{!v.item.Name}"/>
    </p>
    
    <p>Price:
        <lightning:formattedNumber value="{!v.item.Price__c}" style="currency"/>
    </p>
    <p>Quantity:
        <lightning:formattedNumber value="{!v.item.Quantity__c}"/>
    </p>
    
    <p>
        <lightning:input type="toggle" label="Packed" checked="{!v.item.Packed__c}" />
    </p>
    
    <lightning:button label="Packed!" onclick="{!c.packItem}"/>
</aura:component>


9)CampaignListitemcontroller.js:
({
    packItem : function(component, event, helper) {
        component.set("v.item.packed__c",true);
        var btn=event.getSource();
         btn.set("v.disabled",true);
    }
})