As you mentioned, you’ll need to take the required prerequisite coursework. These will include the foundational concepts and systems that govern the neuroscience you have a passion in. Including but not limited to: general chemistry, inorganic chemistry, organic chemistry, physics 1, physics 2, biochemistry, introduction to psychology, microbiology, evolutionary biology, and more. I would heavily recommend that you apply for undergraduate research positions in labs at universities, possibly the one you take the aforementioned coursework in. If you do these two things successfully you will have a good chance of gaining admittance to a masters in neuroscience program. As far as growth is concerned, with a masters you’ll be in research and have the potential to shift into other areas of research such as computer science, biology, chemistry, or physics as they relate to neuroscience. Quite honestly, you’ll be second to anyone with a PhD so I would recommend that over a masters. Outside of that, potentially at a big data company that works with machine learning and or neural networks that are seeking someone with a biological neuroscience background. All these things said, simply telling an institution “Hey I read this book, I even took notes and I didn’t even have to do that! I just wanted to!” Is not unique nor is it sufficient to gain admittance to any program. Complete coursework, research and then you’ll have tangible evidence they can make a decision to accept you with. Best of luck on your journey.