Programatically add Products

Many thanks i really appreciate your help , ok now another thing i have MS SQL database which has a table of categories and Products, i want to fetch it from that DB and insert into nopCommerce DB, how can i achieve this?

My Controller look like this now.

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Web.Mvc;
using Nop.Admin.Models.Catalog;
using Nop.Core.Domain.Catalog;
using Nop.Core.Infrastructure;
using Nop.Plugin.Misc.ProductImport.Models;
using Nop.Services.Catalog;

namespace Nop.Plugin.Misc.Product.Controllers
{
    class ProductImportController : Controller
    {
        //
        // GET: /Default1/
        public void CreateProduct()
        {
            //product service
            var _productService = new NopEngine().Resolve<IProductService>();
            
            // category service
            var _categoryService = new NopEngine().Resolve<ICategoryService>();

            //declare product instance
            Core.Domain.Catalog.Product prod = new Core.Domain.Catalog.Product()
            {
                Name = "DELL 4530",
                UpdatedOnUtc = DateTime.UtcNow,
                CreatedOnUtc = DateTime.UtcNow,
            };
            
            //add product via product service
            _productService.InsertProduct(prod);

            //create category instance
            Category _category = new Category()
            {
                Name = "Laptops"
            };            

            //relate category & product
            var productCategory = new ProductCategory
            {
                ProductId = prod.Id,
                Product = prod,
                Category = _category,
                CategoryId = _category.Id
            };

            //add product category
            _categoryService.InsertProductCategory(productCategory);
        }
    }
}