A single class is too little to really learn anything. As a rule of thumb, a semester of full-time work is enough to learn one "thing". That thing can be wide, in which case you get an overview of the topic, or it can be narrow, allowing you to dive deeper. Anything less, and the only thing you'll likely retain is a random selection of ideas and factoids.
If the degree nominally takes 4 years to complete, you have enough time to learn approximately 8 things. Use one slot for a subject, and most universities will give you an introduction to the topics covered by the subject. Use another, and then you may start understanding the arguments and issues in one subfield.
If the degree nominally takes 4 years to complete, you have enough time to learn approximately 8 things. Use one slot for a subject, and most universities will give you an introduction to the topics covered by the subject. Use another, and then you may start understanding the arguments and issues in one subfield.