Three different starting points
The useful difference between these courses is not which title sounds strongest. It is how much time and prior context you have. A very short beginner course is useful for testing interest; a broader beginner course gives more exposure; the diploma-style fundamentals course asks for a larger commitment.
Choose Practical Python when you are testing the field
A short first encounter is appropriate when you have never coded and do not yet know whether programming suits you. The goal should be to write a few small programs and decide whether to continue.
Choose Python for Beginners for a broader overview
This course reaches across several Python concepts. That breadth is useful when you want to see more of the language before committing to a longer path, but it still needs outside exercises.
Choose Diploma in Python Fundamentals for more depth
The longer fundamentals course makes more sense when you already understand basic programming ideas and are willing to spend more time building a foundation.
The missing ingredient is repetition
Programming fluency comes from writing, debugging and changing code. Whichever course you choose, create small original exercises rather than only following examples.
Decision rule
Pick the shortest course that matches your current level, then earn the right to move deeper by completing a real coding task.