Suppose I do the following:
I code out a very small python program (like no more than five hundred lines of code): I download relevant packages about PyQt5, opencv, numpy, math and matplotlib at anaconda using update commands. In the code, I import PyQt5 them to code out some interface and import other libraries to do some very basic commands (i.e. I do not make changes to the source code.) At the end of the day, I use PyInstaller to convert everything I coded to exe to sell it to someone else for a price.
If I want to keep everything legal, do I need any kind of license for what I am doing? If I do need license, which one(s) do I need? I am kind of lost in all kinds of licenses.