As you have learnt many programming languages it will be very easy for you to catch up JAVA. Initially it’ll take time because JAVA’s syntax is different from other languages and bit long also. So, to learn it first you’ll have to start from very basics. Learning from scratch like understanding the meaning of every line of code. After you’re done with overview then you can start doing simple stuffs like printing ‘Hello World’ and then learn about if-else and then something about operators. Then you again sit and understand syntax and do easy programs like addition etc. After all this you can move ahead and do loops and then basic data structure like arrays. After all this learn about JAVA methods and then you can proceed to learn OOPs.

You’ll get many resources on internet to learn from but since you asked I’m giving some sources.

w3schools: This is my personal favorite place. Head over https://www.w3schools.com/java/ and start learning. You can also use their online tool for beginning practice.

Coursera: You can enroll into this specialization https://www.coursera.org/specializations/java-programming Head over there only after having basics cleared.

IDE: A good IDE is always required. Here is one of the most popular one. https://www.eclipse.org/downloads/

Happy Coding!