Start with Python 3, the differences isn't something that you can't pick up in an hour, and since you won't have existing python 2 code base you probably will n

Start with Python 3, the differences isn't something that you can't pick up in an hour, and since you won't have existing python 2 code base you probably will never need to do that. The biggest issue people are having is to convert their python 2 code to work on python 3. There's virtually no downside to use python 3. All maintained libraries work with python 3.