How to create an array of class type objects?

Yuriy, sorry by my english.

If I understand correctly, you want to create an array of a class, in this case the Transportation class

This do the magic

using System;
using System.Collections.Generic;

namespace ConsoleApp1
{
    class Transportation
    {
        private string name; //name company
        private double cost; //unit price
        private double weight; // Shipping Weight

        public Transportation(string name, double cost, double weight)
        {
            Name = name;
            Cost = cost;
            Weight = weight;
        }

        public Transportation()
        {
            Name = "none";
            Cost = 0;
            Weight = 0;
        }

        public double Cost { get => cost; set => cost = value; }
        public string Name { get => name; set => name = value; }
        public double Weight { get => weight; set => weight = value; }
    }

    class Program
    {
        static void Main(string[] args)
        {
            Transportation[] company = GetTransportations();
            foreach (Transportation item in company)
            {
                Console.WriteLine(item.Name + " => " + item.Cost + " => " + item.Weight);
            }

            Console.ReadKey();
        }

        public static Transportation[] GetTransportations()
        {
            string name = string.Empty; //name company
            double cost = 0; //unit price
            double weight = 0; // Shipping Weight
            Transportation[] transportations = new Transportation[] { };

            List<Transportation> transportationsList = new List<Transportation>();

            while (true)
            {

                while (true)
                {
                    Console.WriteLine("Insert the name of product: ");
                    name = Console.ReadLine();
                    if (!string.IsNullOrEmpty(name))
                    {
                        break;
                    }
                }

                while (true)
                {
                    Console.WriteLine("Insert the cost of product: ");
                    string costString = Console.ReadLine();
                    if (double.TryParse(costString, out double c))
                    {
                        cost = c;
                        break;
                    }
                }

                while (true)
                {
                    Console.WriteLine("Insert the weight of product: ");
                    string Sweight = Console.ReadLine();
                    if (double.TryParse(Sweight, out double w))
                    {
                        weight = w;
                        break;
                    }                    
                }

                transportationsList.Add(new Transportation(name, cost, weight));

                Console.WriteLine("Continue to add products? Y/N: ");
                string continueToAdd = Console.ReadLine();

                if (continueToAdd.Substring(0, 1).ToUpper() == "N")
                {                    
                    return transportationsList.ToArray();
                }

            }
        }

    }
}