You can do something like this instead of your code:
string sqlString = "select top 1 tblPackages.*, tblPackageTypes.Name from tblPackages join tblPackageTypes on tblPackages.TypeId = tblPackageTypes.Id where tblPackages.Id = " + id;
SqlConnection con = new SqlConnection(cnxn); // cnxn is defined
SqlDataAdapter sda = new SqlDataAdapter(sqlString, con);
DataTable dt = new DataTable();
sda.Fill(dt);
FullPackages package = new FullPackages();
package.Id = Convert.ToInt32(dt.Rows[0][0]);
package.TypeId = Convert.ToInt32(dt.Rows[0][1]);
package.AllowedSMS = Convert.ToInt32(dt.Rows[0][2]);
package.TimeSpan = !DBNull.Value.Equals(dt.Rows[0][3]) ? Convert.ToInt32(dt.Rows[0][3]) : 0;
package.Price = Convert.ToInt32(dt.Rows[0][4]);