Won’t work if the card has multiple partitions, also might not copy symlinks properly. dd is the way to do this if you want an exact copy, you just need to be very careful. You can take a disk image, that way you only need one slot.

Work on your own projects and it will come naturally, it’s the best way to thoroughly learn a language (probably JS in your case). Try to really understand the basics (like OOP), it’s knowledge which will both translate to other languages and help you learn frameworks/libraries. Instead of relying solely on tutorials, try reading the documentation, it will give you a more thorough understanding (if it’s good), also stack overflow isn’t cheating, you can’t always remember everything. Trust me, you are already way ahead of others if you plan to take CS.