To improve knowledge and skills in the field of Artificial Intelligence you should work on more and more projects. Working on a project makes you implement all the skills that you acquired and lets you know the area on which you need to work. So, the only way is clearing your basics thoroughly and then working on projects.
If you are a beginner go through this AI Tutorial to learn the basics of AI
If you want to dive deep into AI then you must go through this video tutorial:
For getting a job as an AI engineer you should be a professional in AI and you need to have a certificate for proving it, so, you should go for an Artificial Intelligence Online Course to make your career rise to the next level.