Hey there, I appreciate your eagerness to start creating games in flash but as with most things - it takes a lot of practice - especially if you have never used the program before. There isn't really any other way for me to tell you that you probably won't have gained the skills needed to make a game in 30 days - granted if you have experience with similar languages it might sink in a bit quicker but it's wont make the process of making a game that much quicker.
You need to really buy the program, sit down and learn to use it as much as possible before approaching a project like this. I dare say you could make a very small game (or at least the basics) in 30 days if you stick at it but if you would like to give it a go - then I suggest reading through some of the tutorials here:
http://archives.mcleodgaming.com/viewtopic.php?t=5578 or by searching google for other tutorials.