Having a hard time with the PHP Practitioner series.

I've just started with PHP and I'm relatively new to programming. I've been self-teaching web development for the past 6 months pretty seriously. I spent A LOT of time on javascript fundamentals and decided to try out PHP to dive into the back-end. I'm fairly lost on how everything works together, but watching Jeffery's tutorials makes me feel even more lost. He's constantly reaching for tools that a total PHP beginner wouldn't even know existed and implementing them with hardly an acknowledgment of what they're actually doing and why. Like, I understand arrays and all the array functions just fine. But some things are just going right over my head.

For example: want to add something to the database (a task I couldn't figure out for the life of me despite spending a significant amount of time with his PHP course) then just use sprintf() with some dynamic placeholders. I'm not sure I would have been able to reach this conclusion on my own, nor do I understand why the hell he's using sprintf() in the first place.

I really only know what maybe 2/3 of this code is doing and I'm almost done with the series. Am I missing something here? I feel like I have a pretty solid grasp of basic programming principals, but the way PHP is presented in this series feels like a spaghetti presentation where it's a mix of this, that, and whatever necessary without helping me find a solid foundation of what's actually going on.

It's not necessarily bad, but I wish there was a better explanation for some concepts. Like, if I had an MDN style site to check out functions and syntax. The official PHP manual has been an overall not great experience for me coming from javascript.