I’m glad to hear you like my work I do my best to create up-to-date examples and explanations.
You had a good attempt It’s nice to pass the first time but if you don’t, it’s a good look in the mirror to figure out what topics you are weak. Sounds like you figured out what topics those are so you are on the right track
Take your time to learn the technology, try everything, do labs…look at show/debug commands. Recreate the things you see in my examples. The exam is the final step to verify you understand everything.
Good luck studying and if there is anything, let us know ok?