I started this course recently because I would like to make computer science my profession. Despite this it continues to barely advance, the implementations that need to be done most I have done but the others I have seen that I was blocked and I was looking for solutions on the internet. Should I proceed this way? Or should I start over? Any suggestions are welcome, thanks. I only use the book for the course.
A lot depends on how you learn most effectively. Most people that can't solve a problem and go look up the solution seldom learn much in the process -- they tend to think they did, because the solution appears to make sense, but as soon as they walk away they would be hard pressed to get any further in their solution if they were to try again. But if you are someone that takes a deep dive when looking at a solution with a focus on understanding why the solution works and what steps needed to be taken to get from where you got to the solution, then it can be an extremely effective learning approach.
If you do decide to hunt down someone else's solution, one way to ensure that you really do gain the necessary understanding is to study the solution, then put it aside and, after waiting a few days, try again on your own and see if you can now tackle it.
Firstly, I agree with WBahn's response regarding the approach you should take with the Nand2Tetris course. I would encourage you to try and figure things out for yourself and not deprive yourself of what Nobel prize physicist Richard Feynman describes as "the pleasure of finding things out".
In your post you indicated that you would like a career in computer science, a very broad field these days. You identify yourself as a "beginner", but that is really too vague a characterization to provide any solid advice in pursuing your goal. For example, do you have any background at all in computer programming using a modern language such as C++, Java, or Python? Such knowledge, probably at a little above beginner level, will be needed to complete the course project in the sixth lesson.
I have taught introductory computer science in high school (10th thru 12th grade) for the last few years as a volunteer instructor in the national TEALS program. My students are usually absolute beginners; they have no experience with computers other than as end users. The Nand2Tetris course would certainly not be a starting point for someone at this level. I think the book, while excellent, assumes that the reader has a basic understanding of at least how programming works.
If the above describes your current level, I would be happy to suggest other courses available on both the Coursera and edX platforms which might be a more appropriate starting point.