Macbook Pro will not install update

Hello, I'm having an issue with my Macbook Pro. A little bit about it, its the mid 2012 i7 model wiith the dual core and 8 gigs of ram still running OSX Lion.. I just need to know whats going on, because now some of my programs are not functioning right because I cannot update it. I was still able to update my iphone from it, but I can't do much else, everything is running slow or not at all. My adobe reader isn't working properly either, if anyone has any idea what to do please let me know, I'm an online student and CANNOT wait any longer on it.