This is just a step by step procedure and mostly based on your previous academic qualifications, skills and a full literature review to understand what has been previously done and what is need to be done, with which benefits, how to do it, why you interest you to do it etc. For you basic AI?ML? please kindly read the attached book for the basics/fundamentals?..
Both techniques you have mentioned are huge. It is better to select a specific domain. You can choose it based on your motivation, desire, background, and previous qualification. For example, I am interested in Healthcare / Health Informatics. I have used ML, DL, and CV in this field.