That itself will take you a few days.
If you are focused then may be you can learn the basics in a week.
Yes, since js syntax is a bit familiar with python. If you want to do frontend with js, backend with python then learning both of them is okay. Btw, if you really want js, learn nodejs so that you can do both backend and frontend with it. If you want more backend power, you should learn python first.
Imperitive programming has a tendency to be messy by default because its focused on trying to tell the computer how to do everything, rather than describing what needs to be done.