If you log in to your Chromebook and head over to the bottom right corner, click on where it shows the time and battery. A new box will show up with a few different options; choose the accessibility settings option. Uncheck the on-screen keyboard option. If you have any other things showing up on your screen such as a circle around your cursor, or your screen is extremely magnified, the options for turning those off are also under accessibility settings, and can be unchecked.