Please read Getting good answers to your questions. One of the things that, and the section ‘Search, and research’ in How do I ask a good question? linked at the bottom there, emphasize is to search for posts already covering your concerns before making additional posts in such forums:
I would suggest you don’t want that as someone new to learning to use what looks like Python in modern Jupyter. If you absolutely do, see where it says, ‘you can opt to use NbClassic’ in that thread ‘“In” and “Out” missing from left of code line’.
Additional note:
Be cautious because now you know your training material is outdated. More than likely it doesn’t matter for most things, but it will probably be helpful to keep this in mind going forward.