Repository pattern implementation

Question

I'm in the process of delving into different design patterns and trying to implement them into my daily work routine.

I come from an unstructured world of PHP and not understanding how to utilize it to its potential. I have recently switched over to C# and I'm trying to unlearn some bad habits I picked up through my lack of understanding.

I have some of my WebAPI project, which will grow in the future so I'm trying to plan for that now. Please review the code and see if I have implemented a repository pattern correctly. The code is 100% functional but I put it together out of a few eBooks I'm reading and a few articles I found online.

Simple interface with only one method:

public interface IProductRepository
    {
        ProductViewModel GetProduct(string ProdNum);
    }
}

Product Repository Class:

public class ProductRepository : IProductRepository
{
    private ProductMaterialEntities pd;

    public ProductRepository(ProductMaterialEntities product)
    {
        pd = product;
    }
    public ProductViewModel GetProduct(string prodNum)
    {
        var result1 = pd.products.Where(x => x.ProdNum == prodNum).FirstOrDefault();
        var result2 = pd.ProductImagePaths.Where(x => x.ImageProdNum == prodNum).FirstOrDefault() ?? new ProductImagePath();
        if (result1 != null)
        {
            ProductViewModel product = new ProductViewModel()
            {
                ProdID = result1.ProdID,
                ProdNum = result1.ProdNum,
                ProdCode = result1.ProdCode,
                .
                .
                .
                .//whole bunch of attributes
                ImageCompany = result2.ImageCompany
            };
            return product;
        }
        //return empty ProductViewModel if nothing is found
        return new ProductViewModel();
    }
}

Default controller

public class ValuesController : ApiController
    {
        private IProductRepository productRepository;
        public ValuesController()
        {
            productRepository = new ProductRepository(new ProductMaterialEntities());
        }

        [Route("Product/GetProduct/{prodNum}")]
        // Access via: http://xxxxxxxxx/Product/GetProduct/02130
        public IHttpActionResult GetProduct(string prodNum)
    {
        var productInfo = productRepository.GetProduct(prodNum);
        if (productInfo.ProdID <= 0)
        {
            return NotFound();
        }
        return Ok(productInfo);
    }   
   }