How I learn above technologies and from where I start?
You can learn above technology from the online courses, or YouTube or other platforms which are available for the learning. Online platforms like Coursera, udemy, etc. provide resources for learning it. You can check out. But first, you complete the basics and make some simple apps, then go for these technologies. In starting for it you have to learn different languages like python, as it is more recommendable for it, then you go for some frameworks which are linked with ML. And as you will proceed you will automatically find what to do next. One can also use this technology by java but it is not that much efficient as python.