People get confused about different types of loaves. A baguette is what we generally call a French stick, a long thin loaf or roll made from lean dough. Those which are baked in Paris and other parts of France tend to be a great deal more succulent than the UK versions. A pain is just a generic name for bread or a loaf, whatever shape or style. Most English people associate pain with pain au chocolat or similar but that is probably due to our lack of knowledge of French. Although cooking a baguette might make up the majority of a baguette class in Paris there might be other things to learn to cook, the details of which are explained below.
Not all baguette cooking classes are the same, some are about working as a family baking the bread, some might enough making items like Croque Monsieur and brioche - brioche is quite yeasty bread, usually served in a roll, while a Croque Monsieur is a fancy version of a toasted cheese and ham sandwich. It's worth looking at these little extras to see which is the right lesson for you. It might be possible to find last minute special offers on classes if you go at the right time.
What you learn would depend on who you take the class with, there is a family baguette baking class available for example, where you might learn how you and your family get on under pressure! It's generally a lot of fun too as well. It's reassuring to know that most classes are taught in English and operate in quite small groups.