Welcome!
PyQt4 has been unmaintained for many years, and is not compatible with modern Python; you should use PyQt5 or PyQt6 instead, especially when starting fresh with a new project. If you are following a tutorial for it, I strongly suggest you just find a more up to date tutorial—and I’m sure you can find a lot better than a one with no narration or explanation from a channel with 34 subscribers.
If you do want to try to make this work, you’ve apparently already installed PyQt5, so you could try replacing PyQt4 with PyQt5 in your import statement as QtCore, QtGui and uic are still available and the basics should mostly still work the same. However, if it does anything non-trivial, you’re likely to run into issues that may or may not be easy for a beginner to solve, so again I would strongly recommend finding a more up-to-date tutorial for PyQt5/6 or PySide2/6 5.12/6.2 or above.
Also, just to note, since these questions are about Qt//PyQt and not the Python language itself, you’re likely to find better help on a Qt/PyQt-specific forum. Best of luck!