In regards to finding a project to start practicing, coupled with buying a dev board, I can recommend this course https://www.edx.org/course/embedded-systems-shape-the-world-...

I did it some time ago, the board they use is pretty cheap and it could be a good starting point. Disclaimer: - I did this course (or similar, but same professors and same university) online some years ago, so I assume it has been updated. - I do not get any benefits, monetary or otherwise, for promoting this course or for new enrollments. I just recommend it based on my personal experience.