Beginner here, need a starting off point

A point and click game shouldnt require much. An engine would probably just get on the way.

You probably can make a simple one with java alone, as it oretty much requires only the ability to get input and draw images which i assume are provided by java built in.

If you need more advanced features, googling will usually find comparisons and suggestions which you can then compare. I have practically no experience with java so cannot give any suggestions.

How much graphical imagery will there be? If you have a lot of art assets planned, then I say use a game engine such a jMonkey.

If you want to use vector graphics only, which can be created by even an early stage programmer with a lot of work spent on it, then you would have something easy to size on most or all device display screens and better lend itself to cross-platform. With vector graphics, then a Java IDE would be okay. If I went that route, then I would target the Java Runtime Environment and give the player the option to install the JRE downloaded with the game as you prepared it for the user. Packaging the JRE with the game is fine as long as you notify the user of the option to install it or deny it and display the license agreement. This JRE implementation makes Java developed games very cross-platform, perhaps the easiest way for the Java programmer to implement cross-platform.

There are many Java based communities for 2D game development, for both game engine and IDE there are many, especially text heavy usage games with IDEs or kits.

Before you start making games, you need to use Java to code 3 to 5 simple applications such as data base, letter display/editor, index with scroll, and encoder. These are essential skills learned for the long term by any game developer. They also have the advantage of giving you experience to create code which can be reused in your strategy game.

I think the strategy games are easy to program, but not so for balance - the design is important.

Start with the design and prepare your game well from that point of view (programming shall be easy).

Knowing some basics about units, buildings and all this staff prepare some (prototype?) graphics and start programming.

With some Java knowledge you may just try to target Android with Google's SDK.

So you may make your own game and teach something about the (indie) publishing as well.