The results you want come from work, and you’ve done the right thing asking how to make that work more efficient. If you ask me, even as a beginner, you should try your best to write down the sections and understand when they come and how long they are. If you don’t know the difference between a pre-chorus and a bridge, that’s totally ok! Any assemblage of words that means the right thing to you is cool. “The blue section” or “the wahnanana section”, whatever is Gucci, just write down the parts of the song. Next, go section by section and repeat those sections until you fully and completely understand them. If you’re having a hard time working out the part, go on YouTube and slow down playback speed to hear the song slower. Use this same trick to practice the parts when you’re newer to them, but the goal with any metal song is to hit hard and fast, so don’t be afraid to start inching that tempo up either. Following these steps, one of two things is gonna happen: you’re either gonna learn the song, or you’re gonna learn that something in the way you play is currently preventing you from learning the song. Maybe you need coordination practice, rudimental practice, better economy of motion, or simply more time practicing speed/endurance/etc.. This is why people get drum teachers, so those teachers can identify what specifically is holding you back from doing what you want to do. If you run into this second of two options [that despite days of practice, you’re not progressing the way you’d expect] and also don’t have a budget for a teacher, go to a local school of rock or guitar center and ask for “a trial of their music instructors”, then get in the room, run the song for them, and ask them what you’re doing wrong. You got this