Install Flash on one computer and then use Flash, or somehow transport it to another computer. Because I'm planning to buy a new computer, but that woudn't be for a while, so is it possible to change computers?
Yes, it is possible. You can have your current copy of Flash activated on two computers at the same time. If you are moving from one computer to another, then on the old computer, go to the Help menu and select Deactivate. Follow the instructions. Install Flash on the new computer and activate that installation.