I don't know of any online means for using Flash. You can certainly learn it from online tutorial resources, but the program is not available in that way as far as I know. Aside from using a free 30 day trial for all you can get out of it, there isn't much choice other than to purchase Flash in one way or another. You can purchase CS6 or subscribe thru the Creative Cloud. A subscription might be your best bet, but even then a trial would be advisable before spending any money to make sure your machine is up to the task and your interest remains afterwards.