In text classification, the goal is to find the best class for the document. Multinomial Naive Bayes or multinomial NB model, a probabilistic learning method is a supervised learning method.
Please, use the pdf file for more detailed instructions. For worked example look at 44 slide. Use Naive Bayes model with TF/IDF algorithm to solve text classification problem. Be free to choose any task for applying this algorithm. The datasets can be taken from broad set of links e.g., kaggle, etc. For testing purposes you can use email spam filter dataset from here.