As I said 100 times here... Read, learn, watch tutorials, look at codes, try to make something, anything, but alone, without any help, discover things, discover ways that things can be done, and start with smaller stuff, and be consistant, learn everyday, for the same period of time, or more every day, depending on how much time do you have for that... And love what you do, love your codes, and, the most important thing, NEVER, like NEVER give up!
As supporting material to SoloLearn:
Another look at Java with problems:
Specific challenges related to games:
There are many fields there and you can try the problems in various languages to get a feel for what *you* like best.