Where should I start?

I agree with the course recommendations from @Th_o_Vy_Le_Nguy_n. You also don’t mention whether you have any programming experience yet. All the courses on that list require that you already know how to program competently in python. If you’re not already a python programmer, you should also consider taking a python course. There are a number of them on Coursera, as described on this thread. If you are already an experienced programmer in other languages like JavaScript, Java, C# or C++, then you may be able to learn python “on the fly” by spending a couple of hours on some of the online tutorials. But if you are completely new to programming, it would be much better to start with an “intro to python” course.