I just got a new MacBook Air because my ten year old PC had gotten loaded up with so much malware/spyware/virus that it became unusable and it gave me a excuse to buy a new computer and I decided to try a Mac. I am getting a notice that Adobe Flash updates are available. I do not want to load this computer up with any problems. should I update or if not how can I get this message to stop popping up when I boot up?
Did you install Adobe Flash yourself? If not, then you should not have Adobe Flash installed as Apple does not have it installed with new Macs (unless they have changed). So, if you did not install it and are getting a message, then it might be some sort of a scam from a website (unless it is telling you to actually install it to watch a video).
If you did install it, then yes, you should update it (see dante12's post for where to get it). If you don't want to have it installed, then you could uninstall it. Lastly, you can turn off "Notify me to install updates" from within the Adobe Flash "control panel" in the System Preferences under the Updates tab, but I would not advise it...either update it or uninstall it.
If you don't have Flash installed (you will see a "control panel" for it in System Preferences), then something else is going on.