Since you are already familiar with Java, then try finding some simple game video tutorials (like pacman) that walk you through the entire process from start to finish and follow along line by line. This will get you familiar with the concepts that go into a game.
From there, start making very small tests where you implement just one aspect of a game at a time.
Some possible examples:
- Create a simple game loop that simply paints a circle.
- Next make the circle move across the screen from one end to the other.
- Next make the circle detect the edge of the screen and send it back the other direction when it hits an edge.
- Then get input from the user and make the circle move with the arrow keys instead of moving on its own.
Etc.
In just that little bit you’ve covered a game loop, updating, painting, basic collision detection, user input, etc all key components to creating games.
So instead of focusing on the exhausting task of “making a game” (OMG!!! :o) you can think about creating smaller individual puzzles for yourself that you have to solve. Focusing on these simpler tasks will also allow you to search for specific topics and find better explanations and tutorials related to what you want to know. For example, searching for “how to move an object with arrow keys in java” will likely provide much more useful results than “how to make a game in java”, which is an extremely broad topic.
Finally, once you start working on more complex games, it’s a very good idea to keep creating “side-projects” regularly where you work out a particular task in isolation without trying to figure it out inside of your more complex game. Once you know exactly how it works in isolation, then incorporating it into your actual game will be a whole lot easier.