Learnable parameters in DNN
In neural networks in general, and in deep learning algorithms (CNN, DNN, etc.) that are also based on neural networks, learnable parameters are parameters that will be learned by the model during the training procedure such as weights and biases.
You can generate learnable parameters for each layer of your model.
DNN is a deep neural network. What I understand that when a neural network becomes deep, it can be said that it's a deep learning model.
So, to compute a DNN or CNN learnable parameters, you can build your model using Keras. It can automatically generate the models learnable parameters for each layer. When you complete building your model, type model.summary(). It generates a list of learnable parameters when you run it.
This link builds a DNN model using using Keras.