what should i learn, what is the difference

of course java

html css javascript
python
sql

Depends on your purpose I can give different advices. 

Java is good for now for mobile technology, programming.

But python is almost for any other stuff.

Python is much more beginner friendly, you can always learn other languages after learning programming concepts through python.

need math for phyton or java?

Try them both.

I prefer Python, but I haven't used Java for a long time, so maybe my opinion could change if I try Java again.

But yes, Python is beginner friendly, you can quickly build things and be productive. With Java you need to learn OOP before you start to understand the language more.

We are in the energy era. Don't use python

The selection of the language depends upon the type of application a programmer wants to create. Analyze your program, requirements, select a language, and go ahead with that language. If you are a raw handed in programming, Python may be a good choice. Nevertheless, if you also want to learn the Java programming language, it will be good if you have basic knowledge of object-oriented programming C++.The future of the Python language is very bright. So, we suggest you to start putting your hands-on Python. It is an easy and interesting programming language.

python if you're interested in AI