Flash is as safe as Adobe makes it. There are occasional security updates regarding it. Some animated websites require it, while others do not. Play around with websites and see if any really needs it that you really need access to. If you find some do, you should also recommend they consider switching their Flash to HTML5, which eats up less processor cycles, and because it is maintained by the open source community is more likely to be secure. Don’t click on animated advertisements and banners, unless you are absolutely certain they are legit. Don’t believe any popup saying you should install asking you to install anti-virus software. Just close those windows with the red button in the upper left corner and proceed going through websites. If they make a window you can’t close, bookmark any sites you are on, and quit the web browser.