You should create a user account for you and always study under your user account.
Click the Settings menu from the menu bar > User Account > click Add New User
The Add New User dialog box pops up > enter user name > click OK
A message box pops up to confirm the addition of a new user account > click OK to finish
The user name should between 5 to 15 characters long. It should be started with a letter and followed by letters, digits and under scores ( _ ).
Adding a user does not make that user the current user automatically. You have to switch to that user to make that user the current user.