How does one bring in the confidence to apply for a job position without having the right skills. There many cases where employees take up a job which is totally irrelevant from the previous and still strive.

I am currently a Project Engineer with a Mechanical Engineering degree working in the Oil and Gas industry. I am hoping to transition into becoming a Artificial Intelligence researcher. How do you think is the best way to achieve this? Do I need to spend a few more years taking another degree for it?

What do you suggest for a university student to do in their free time other than assignments , etc. How do you start a career in digital marketing .