MalwareTech Video on Getting Started with RE
I hate making videos, so I'm linking to a video by Marcus Hutchins, known as the person who killswitched Wannacry, among many other things, that does a great job of explaining what it takes to learn RE.
While he talks about finding material that works for you and going with that, luckily, there is a better way forward for your first steps than teaching yourself: this course! Glad you are here.
For legal reasons: Marcus does not endorse this course or this site, and I don't endorse him whispering to my students, and yet here we are.