Simply trying to input notes

My stepdaughter and I are new to the program. She uses it at school and has no issues. We used it at home once without issues but now it's going crazy. We open a new project and select the pen tool. We click to enter a single note and it goes crazy, entering infinite notes. It repeats and fills the whole screen with notes just from one click. Is this just a button we've pressed on the keyboard at some point by accident? We've uninstalled and reinstalled but the same problem persists. Please please help as she has school work to complete.