Sorry if it sounded like that. What I meant is that the 2d matrix representation with shape (n_samples, n_features) actually goes beyond scikit-learn and python(ex: dataframes in R or Julia), it is the standard representation of data in Machine Learning so it is assumed that someone who wants to do Deep Learning should already be familiar with it. That is why I thought you should start with something simpler than Deep Learning to get used to these concepts. Scikit-learn is a good option because it has more tutorials/examples/videos and more beginner friendly documentation in general.