How should i do this?

Sooo… A Long time ago. I came up with a game idea, where you basically explore space.
The Idea seems simple but how i come about this is difficult. ??? ???
I’ve been using Java (Eclipse) for a while now.
I’m pretty good at it. However I’m new to Game Development.

I would like to make a finite randomly generated Map, (Kinda like an RPG style).
This would be probably like an image or a black screen to represent space.
This part is simple. And i think i can do this.

The Hard part is making squares (Represents stars) in the map. They should be big, probably 60X60.
These would be randomly generated and scattered throughout the map.

I Should also be able to interact with these stars. (Simulate gravity, click for information, etc.)

From there on. I can (Probably) tackle the rest by my self.

If you could just guide me toward the right tutorial or whatever, It would be most Helpful. Thx…