Codecademy teach us to download Miniconda (https://www.codecademy.com/articles/install-python3), however it is not very clear how should we use it and how it works. It seems that downloading python and a text editor is enough. When Miniconda should be used?
The link you reference actually contains instructions on installing either “regular” Python - i.e. the version released by the Python Foundation - or Miniconda.
If you’re learning Python, you can realistically choose either. There are advantages and disadvantages to both regular Python and Anaconda/Miniconda. If you’re working through a course here and one of the off-platform projects suggests you use one or the other, then go with the suggestion.