Need help in User object Test class

@isTest

public class Test_MCShopsPdf {

    @isTest   

    Public static void test(){

        Profile pf= [Select Id from profile where Name='System Administrator']; 

        String orgId=UserInfo.getOrganizationId(); 

        String dateString=String.valueof(Datetime.now()).replace(' ','').replace(':','').replace('-','') ;

        Integer RandomId=Integer.valueOf(Math.rint(Math.random()*1000000)); 

        String uniqueName=orgId+dateString+RandomId;

        Id owner_Id;

        User managerInfo;

        User uu=new User(firstname = 'ABC', 

                         lastName = 'XYZ', 

                         email = uniqueName + '@test' + orgId + '.org', 

                         Username = uniqueName + '@test' + orgId + '.org', 

                         EmailEncodingKey = 'ISO-8859-1', 

                         Alias = uniqueName.substring(18, 23), 

                         TimeZoneSidKey = 'America/Los_Angeles', 

                         LocaleSidKey = 'en_US', 

                         LanguageLocaleKey = 'en_US', 

                         CurrencyIsoCode='USD',

                         ManagerId='0057F0000039QXUQA2',

                         ProfileId = pf.Id

                        ); 

        insert uu;

        System.runAs(uu) {

            List<OrderItem > lstoplitm= new list<OrderItem>();

            Account a = new Account(name ='testac1',BillingCity='BillingAddress',BillingCountry='India',BillingStreet='test BillingStreet',BillingPostalCode='12345',BillingState='Haryana',Type='Reseller',CurrencyIsoCode='USD', Business_Status__c ='ACTIVE');

            insert a; 

            Product2 prod = new Product2(Name = 'Laptop X200',Family = 'Hardware');

            insert prod;

            Id pricebookId = Test.getStandardPricebookId();//This is available irrespective of the state of SeeAllData.

            PricebookEntry standardPrice = new PricebookEntry(Pricebook2Id = pricebookId, Product2Id = prod.Id,UnitPrice = 10000, IsActive = true);

            insert standardPrice;

            //PriceBook2 pb2Standard = [select Id from Pricebook2 where isStandard=true];

            Id SpricebookId = Test.getStandardPricebookId();

            PricebookEntry pbe = [ SELECT Id,Product2Id,Pricebook2Id,UnitPrice FROM PricebookEntry WHERE Pricebook2Id = :SpricebookId  AND isActive=true LIMIT 1 ];

            Order o = new Order(name='test opp1', Status='NA', Offer_Status__c ='Validated',  AccountId=a.id, CurrencyIsoCode= 'USD',EffectiveDate = Date.today(),Pricebook2Id = SpricebookId, OwnerId = '0057F0000039QXUQA2');

            insert o;

            owner_Id =  o.OwnerId;

            OrderItem op=new OrderItem (PriceBookEntryId=pbe.Id,quantity=1,Orderid=o.id,UnitPrice=pbe.UnitPrice );

            lstoplitm.add(op);

            insert lstoplitm;

            Test.startTest(); 

            //Create Controller instance 

            MC_Shops_PDFController testOrdPlanMCShop = new MC_Shops_PDFController(); 

            testOrdPlanMCShop.getOrders();

            testOrdPlanMCShop.getOrderItemList(); 

            testOrdPlanMCShop.getUserInfo();

            Test.stopTest();

        }

    }

}

 here is the apex class :

public class MC_Shops_PDFController {

    public List<OrderItem> orderItems { get; set; }  

    public Id orderId;

    public Id owner_Id;

    public MC_Shops_PDFController(){

        orderId = ApexPages.currentPage().getParameters().get('id');

        orderItems = new List<OrderItem>(); 

    } 

    public List<Order> getOrders(){

        List<Order> ordObj =   [select Id,Project__c,Account.Name,Account.Email__c,OrderNumber,Name,EndDate,Offer_Participants__c,EffectiveDate,OwnerId, Owner.Name from Order where Id = : orderId];

        if(ordObj.size()>0){

            owner_Id = ordObj[0].OwnerId;    //NOT Covering this line

        }

        return ordObj;

    }

    public List<OrderItem> getOrderItemList(){

        return [SELECT Id, UnitPrice,ListPrice,Additional_Amount__c, Quantity,Material_No__c, OrderId,Product2.Name,Note__c FROM OrderItem WHERE OrderId = : orderId Order by Product2.Name DESC];

    }  

    public List<string> getUserInfo()

    {

        String managerId = owner_Id;//'0057F0000039QXUQA2';

        String toCheckNull = NULL; 

        User managerInfo;

        List<string> mgrInfo = new List<string>();

        while(managerId != null)

        {

//NOT Covering this line

            managerInfo=  [Select Id, ManagerId, Manager.Name FROM User WHERE Id = :managerId] ;      

            managerId = managerInfo.ManagerId;

            toCheckNull = managerInfo.Manager.Name;

            if(toCheckNull != null && owner_Id !=null) {

                //mgrInfo.add(managerInfo.Manager.Name+' / ');

                mgrInfo.add(' / '+managerInfo.Manager.Name);

            }    

        }

        if(!mgrInfo.isEmpty()){return mgrInfo;}

        else return null;

     }  

}