I have some MacBook Pro issues!?

Hi! I just got a new MacBook Pro for my birthday and I really love it. It has been working very well, yet I have a few minor issues. We bought the computer at Best Buy, and we were offered more memory with the computer. The memory had to be installed onto the computer by the "Geek Squad." I've noticed some minor problems with the computer since yesterday when it was installed. For example, occasionally the computer will turn off when the screen saver appears. Is there an easy remedy to this? Also, today the LCD screen began to shake and the screen was a little fragmented as if it had been broken, but then I quickly turned it off and back on. Could any of this be a side effect of loading more memory on? I'm not all that familiar with computer vocabulary, so I apologize for my ignorance on these issues. Any help would be appreciated.