I am new too programming in Java
I am going to repeat something that has probably been said many many times and probably you have also been told previously.
I am not sure if you have programming experience in other languages, but even if you do. By starting at the beginning and working through the syntactic changes this will provide you with a very good base to develop into more complex games. I am not saying you can't start on a complex game...just that it means you are dealing with an additional workload of all the associated mechanics of game design being placed on top of your learning curve in Java. Why make work harder for yourself? By starting small you should be able to move onto much larger things very rapidly with the essential building blocks having been learnt.
There should be a lot of websites out there that have code samples as well coded games that you can utilise in your learning. I wish you the best of luck and welcome to Gamedev.
The direction I am choosing is a multiplayer/resource game but I need an original idea.
You and the other players in the game are different types of Jellies. Your resources to collect are water, jelly crystals and lifesparks. Jelly crystal come in different colours. With the right colour jelly crystal you can make mobile jelly resource collectors and different types of warrior jellies. Different combinations of the resources allows you to create changes in your own jelly self thus being able to create new type of jellies. Ingestion (a form of research) of different components enables you to learn new jelly types to create. The goal -- to consume the other players before they consume you.