Thank you to those taking the time to help me. I've solved my problem . In my Tapped event, I pass the "order id" to the 2nd page using [QueryProperty] and bind the View Model. Please see code.

Page 1 ListView Event code

private async void Orders_ItemTapped(object sender, ItemTappedEventArgs e{
try
{
    var order = (WarehouseOrder)e.Item;
    await Shell.Current.GoToAsync($"{nameof(WOrderItemsPage)}?Id={order.Id}");
}
catch (Exception ex)
{
     await DisplayAlert("Error", ex.Message, "OK");
    throw;
}}

Page 2 Code Behind

[QueryProperty(nameof(OrderID), "Id")]

public partial class WOrderItemsPage : ContentPage{
private WOrderItemsVM vm;
private long orderid;

public WOrderItemsPage()
{
    InitializeComponent();
}

public long OrderID
{
    set 
    {
        orderid = value;
        vm = new WOrderItemsVM(orderid);
        BindingContext = vm;
    }
}
private void Order_ItemTapped(object sender, ItemTappedEventArgs e)
{
    // Future use to populate OrderItemDetail Page
}}