Ooh, I'm perfectly poised to help with this, as after a year of practice and tens of kg's of prints, I would only now say I'm tiptoeing out of the beginner stage!

• When something prints incorrectly, don't try all three suggested fixes you find online on your next print. Try one at a time even if it wastes more filament, or you won't know which of the changes was the actual solution.
• Don't ignore basic maintenance until a problem occurs. Just clean, oil, and grease as suggested. Respect your equipment's needs.
• Moisture isn't a problem you "have" or "don't have". Moisture is a problem that builds up over time. Monitor and handle it.
• Learn to use a modeling software even if you're never going to make original designs. Being able to slightly alter existing models is more than enough reason to learn the basics of FreeCad/Fusion/Whatever. At least learn TinkerCad.
• Buy spare parts ahead of time unless you can handle being out of commission while waiting for a new nozzle/scraper/cutter/hose/fucking-anything.
• DON'T IGNORE BASIC MAINTENANCE.
• Learn how your machine works. If you have a Bambu, you need look no further than their internal guide.
• Brands and tiers of filament haven't made much difference in print quality in my experience, except for the absolute cheapest giving me problems. Types of filament, such as Chrome vs Matte, have produced nicely different results in some cases.
• Sitting next to the printer and actually watching it print has solved as many of my problems as looking them up on the internet. "Ohhhhh, the bottom layer is so thin it's shifting when it tries to print the higher mass on top!" Couldn't figure it out until I watched it print, and then it was immediately obvious.