C# Get Dataset Column Value

Can someone please help me to figure out the value of the dataset column in C# ASP.Net.
I need to assign SPECIFIC column number values to SPECIFIC textboxes.
This is how I did it but it doesnt let me to use Table.
I created a Dataset in Visual Studio and called it MyDataset.

  string connString = ConfigurationManager.ConnectionStrings["App"].ToString();
                SqlConnection conn = new SqlConnection(connString);
            conn.Open();
            MyDataset ds = new MyDataset();
           this.SN.Text=  ds.Tables[0].Columns;