I'm not sure how old 7th grade is, but if that's over 12/13, then you should be able to get a part-time job. It's not that hard to do one, even a simple one like newspapers, then save up to buy a game (or toolset guides, although if you spend time looking you can find good ones online). So for example, you could buy the original Neverwinter Nights, which will be very cheap right now. You don't need the latest game if you are just starting to learn to mod / make games: NWN1 will serve you very well, and it won't be too expensive. And places like nwvault has great guides because people have worked on the game for such a long time.
That's the practical, programming side. Later on, when you have learnt to use these tools, you might find that your stories are not very interesting, or people don't seem to have fun playng your modules. For building up your creative side, it's not finding "guides" and learning "lessons", it's more like playing lots of games, reading books, watching films that all enhance your literary instinct.
Ultimately, though, if you're persistent, then it will work out.