After completing the trailhead for Lightning components, I'm trying one  in my sandbox now.   I'm missing something, and maybe it's my Attribute in the Component, but I'm not sure?  My output doesn't produce the {!v.Transactions[0].name} field (just the "[Transactions List...]".

Component

<aura:component implements="forceCommunity:availableForAllPageTypes" access="global" controller="ctrl_TransactionList">
   
    <aura:handler name="init" action="{!c.doInit}" value="{!this}" />
    
    <div class="slds-page-header" role="banner">
    	<div class="slds-grid">
        	<div class="slds-col">
   				[Transactions List...]<br/>
                <ui:outputText value="{!v.Transactions[0].name}" /> 
            </div>
        </div>
    </div>
    
</aura:component>

Componenet Controller

({
	doInit: function(component, event, helper) {
		console.log('doInit...'); 
        
       
        var action = component.get("c.getTransactions");
        
        action.setCallback(this, function(response) {
            var state = response.getState();
            if(component.isValid() && state === "SUCCESS") {
                component.set("v.items", response.getReturnValue());
            } else {
                console.log("Failed with state: " + state);
            }
        });
        
        $A.enqueueAction(action);
	},
})

Apex Controller

public without sharing class ctrl_TransactionList {
    
    @AuraEnabled
    public static list<Transaction__c> getTransactions() {
        return [SELECT id,name,Payee__r.Name FROM Transaction__c WHERE id = 'a0T2A00000LDUQf'];
    }

}