if your logic and math skills aren't that good yet check out project euler. This will teach you some maths and when you finish a problem you can compare your implementation against their reference and optimised implementations. This might give you a better idea of what you aren't doing very well at this point, as they explain why their algorithms are the way they are as well.

Other then that I'd say try to make breakout or pong on your own without the tutorials from a book.

Programming is a lot of reading of maths, physics and general algorithm design, untill you understand the problem completely and can come up with a solution. Even an experienced programmer often has to read up on a lot of stuff just to understand all aspects of a problem he hasn't tackled yet, the only real difference with a novice is that he knows he has to do that.