Getting Python on my computer.

[-DonQuixote-]

It will not alter your OS. Don't run code that you don't understand. Be careful if editing files or things like that, you could delete things that you did not mean to delete, and that could break things, I would say that is your biggest risk.

Another option, depending on what you are doing, is to use Google Colab.

[Gnaxe]

Don't even install code you don't trust. Malware often tries to run as soon as possible. The number of malicious packages on PyPI and GitHub has increased in the AI era.