Is this a valid way of training a model ? training loss in 1.1921e-07?
Loss is just a sum of errors that your model makes, so lower values are desirable. In your case, the training accuracy is 1.00, meaning that your model is making perfect predictions during training. No mistakes - no loss, so this is to be expected.

However, having 100% accuracy in training is usually an indication that the model has become too familiar with the training data, effectively memorizing it instead of learning to generalize. Such a model will most likely fail to make adequate predictions on data it hasn't seen before. Unless your validation accuracy is also around 100%, then you're severely overfitting. Great explanations that will get you started on interpreting loss and accuracy can be found here.