Hello,
You can use the 
OrderInfoProvider.GetOrders(string where, string orderBy) method with the appropriate where condition. To filter orders of some user, you can the 
OrderCustomerID column and to get orders with some order status, the 
OrderStatusID column can be used. To see all available columns please take a look at the 
COM_Order table.
            
string whereOrder = "OrderCustomerID = " + customer.CustomerID;
// Get the order
DataSet orders = OrderInfoProvider.GetOrders(whereOrder, null);
if (!DataHelper.DataSourceIsEmpty(orders))
{
      foreach (DataRow orderDr in orders.Tables[0].Rows)
      {
           // Create object from DataRow
           OrderInfo order = new OrderInfo(orderDr);
      }
}
Best regards,
Michal Legen