My handle on this forum is ExplosionsHurt. Some people may remember me from this thread from 2 years ago, in which I made a flash game in development, got everyone's hopes up, and then left without a trace.
Yeah, that probably wasn't my proudest moment. The truth is that I had burnt myself out of flash game development, and it eventually got to the point where I forgot about the game entirely. I jumped into the flash development scene with so much raw energy and zeal at the start of it that as soon as I started running into problems that energy started working against me and I got extremely frustrated. I was jumping into it too fast; so fast that I ended up crashing into the metaphorical wall of flashdev bugs at much too fast of a speed.
So it is two years later that I find myself back onto this forum again - I was e-mailed by a person who reminded me about the game. And I read the posts that have been posted here, and they starkly remind me of the exact same position I was in two years ago. You've downloaded all the necessary tools you need. You're in front of your computer, raring to jump into the wonderful yet cruel world of flash game development. You have dreams of making the next The Last Stand or Elephant Quest. This is my advice on how to best proceed. Do what you want with it.
Take it slow. Maybe the first week all you manage to do is make an enemy fall down the screen. That in itself is an accomplishment! Don't try to work too fast. Work slowly - understand every portion of the code you are writing. And if you don't think to yourself, 'Why is this going so slow? Argh!' then you'll find the journey of flash game development a rewarding experience.
It's OK to be frustrated. My first bug was in making the aforementioned enemy move down the screen. I couldn't do it, and was frustrated immensely at this bug. That's fine. Everyone gets frustrated time to time. It's how you deal with it that matters.
Set your goals low. Don't try to make the next Zombie MMO for your first game. In fact, don't even try to make a platformer. Set a realistic scope - look at your current set of qualifications, and ask yourself: "Is this something I can do?" I'm not saying don't dream; I'm just saying to be realistic in what you can and cannot do.
That's pretty much it. This ended up being a lot longer than I was expecting it to be. It's mainly for my own sake really that I wrote it - this post doubles as my principles for development as I get back into making flash games.