Hardlines is fairly easy to learn.
Cosmetics can be a headache, as well as some of the beauty products, but it can be learned.
Chemicals, pets, stationary, appliances, domestics, sporting goods, toys, infants, and market are all simple.
Electronics can be hard, particularly when you get to books and DVDs. You're going to need a device to help you through that.
Softlines? Forget about it. You would have an easier time trying to learn to read Japanese. The team members who have learned it though have my unending respect and admiration.