If you like instant gratification you may be better off with something simpler to use and more visual such as Construct 2 or Game Maker (or perhaps the free alternative ENIGMA, but I don't know much about it). These types of packages are pretty capable and would be more than able to handle a text based RPG with simple graphics, and they're able to target all the platforms you're interested in. You would also find it much more approachable, especially if you've been struggling with your initial programming efforts. Both have free trial versions and are pretty reasonably priced.

Otherwise if that doesn't interest you I'd probably agree with the above that Java may be the simpler of the two options for you to get started with.

Hope that helps!

I would like to point out that if you create the game with javascript, you can run it in the browser. If you go with something like libGDX then you are writing it in Java and converting it into javascript, so there are more layers to confuse you, but you can support many different platforms.

However, this doesn't address the problem of creating a fun game. I am of the belief that if your prototype game with crappy graphics and hacked UI is not fun, no amount of polish is going to help. So going with a framework like libGDX or GameMaker to prototype as easily as possible is a good idea. Once you have the game it is a lot easier to port it to different platforms. Until you know what you've got you might not even be sure which platforms should be supported.

Just my two cents.