Answer 1

If you want to go in AI ,data Scientists etc then python is best for you.python is very simple that's why is use for AI and for data science.Because AI or data science is also complex thing so it is necessary to use simple and easy languages for it.
Java is mostly use for android development ,games , operating system,other big application you can done with java. The reason behind it is very famous now days 'write once run anywhere'.