Apex Class:

public class SampleAuraController {
    
    //Properties
    @AuraEnabled public String FirstName {get;set;}
    @AuraEnabled public String LastName {get;set;}
    
    @AuraEnabled
    public static SampleAuraController getData() {
        SampleAuraController obj = new SampleAuraController();
        obj.FirstName = 'Biswajeet';
        obj.LastName = 'Samal';
        return obj;
    }
}

Lightning Component:

<!--Sample.cmp--> 
<aura:component controller="SampleAuraController" implements="flexipage:availableForAllPageTypes,force:appHostable">
    <aura:handler name="init" value="{!this}" action="{!c.doInit}"/>
    <aura:attribute name="obj" type="SampleAuraController"/>
    <!--Component Start-->
    <div class="slds-m-around_xx-large">
        <strong>First Name : {!v.obj.FirstName}</strong>
        <br/>
        <strong>Last Name : {!v.obj.LastName}</strong>
    </div>
    <!--Component End-->
</aura:component>

Lightning Component JS Controller:

({
    doInit : function(component, event, helper) {
        var action = component.get('c.getData');
        action.setCallback(this,function(response){
            var state = response.getState();
            if (state === "SUCCESS") {
                var result = response.getReturnValue();
                component.set('v.obj', result);
            }
        });
        $A.enqueueAction(action);
    }
})

Output: