Kelly Hopper,
If you have any antivirus software on your MacBook, I would strongly recommend that you remove it. There is no need for it, and it might itself be causing the problems.
If that doesn't work, try repairing your permissions. Open Disk Utility, select your Hard Drive on the top left and click "Repair Disk Permissions".
Check that all your system is up-to-date using Software Update in the Apple menu, too.
Applemacster