How to truly get a hang of Korean sentence structure? ( 3 questions in post)

To keep it short and simple with basic phrases I understand the sentence structure well like with “ I want to eat pizza” it would instead be “ I pizza eat want to” but with more complex phrases like “ I want to go outside because the weather is nice” I just struggle to remember where everything goes with similar phrases? In this case is it just practice makes perfect or are there certain practices yall would suggest?

My second question that I thought I would add instead of making a second post is how do you get good at reading quickly? I understand for some reading a lot may help but is this the only method that most people use? Even when I read a lot it still feels like I read slowly

My last question is what formality of vocab should I learn? I started off with learning casual, polite, and formal. Which was fine until I started adding more and more words. Would yall suggest to just learn polite words and then slowly move onto casual as I get more experienced?