You should never try to just 'learn by yourself'. Always use the forums when you have some trouble. That's why they're here. I remember programming back before we had the internet, and having to figure out any problems entirely alone - that's not an experience I'm eager to repeat. (If ever anybody says that people depend too much on the internet now and forget that we used to manage fine without it, I always reply, 'No - we
didn't manage fine without it!')
But the time to start trying to 'create your own unique things', I'd say, is immediately. The most successful game I made in my teenage years (most successful both in terms of how popular it was and how much we enjoyed making and playing it - you can download it
here, though it's so old it doesn't tend to work on modern computers) started when I got a new programming language (Blitz Basic), and on the first day I got it I made a little arrow fly around the screen by turning and thrusting, and then made the arrow fire bullets. A few days later we turned the arrow into a ship, and added a second ship, and added some collision detection with the bullets. Then we added a level that they could fly around, then a split screen. Then we added bombs they could drop - this was all in the first month, and we kept adding bits and pieces for a year until we had a nice game. But I still tend to start games in the same way - stick a character on the screen, and start making it move. It can get more complicated later. I suspect that whatever kind of game you have in mind, you have the knowledge to do the first thing that needs programming about it. You can get more complicated later, and more ideas will suggest themselves along the way, and you might have more idea of what you need to do when the rest of the game is already there, and you'll be an a position to ask people on the forums how to accomplish the effect because it's a current need rather than just a far-off idea.
I think you're looking at it the wrong way - if you look at the tools and think "What can i do with this?" you'll end up with _much_ less creative ideas.
I don't think that's necessarily true. Maybe it works differently for some people than others depending on how our minds work, but if I just start with a blank slate and try to think of a game to make, the only ideas that ever come up are 'a game like this game I've already played'. My most original game ideas have come by thinking about what a certain programming tool might lend itself to - I guess because that's when the game idea is coming from something other than an already-existing game. I imagine 'Fantastic Contraption', for instance, came about because somebody looked at a physics engine and wondered what they could do with it.