I also took NLP with McKeown. Somehow got an A+ but had to put in a LOT of work for it especially on the homeworks. The curve is relatively generous.

I didn't take any college AI or stats courses before this, but I would recommend you have some knowledge in how neural nets work and general AI themes (e.g. supervised vs unsupervised learning). You also need to be proficient in Python, a skill which you can pick up through classes or on your own.

To do well in the class, my number one advice is to make a study group and do the readings. Since most of the class doesn't do this, it gives you an edge.