The Cornell Note Taking Method is done by dividing the page into three parts.

First, from left to right, draw a line that is about 30% left and 70% right (meaning the right side has more space). From the bottom, leave about 20% of space.

The 30% space on the left is for writing the main ideas and key questions. The 70% space on the right will be used to write key ideas & words, important things (such as dates, people,etc), Formulas, and diagrams.
The 20% space on the bottom is for writing the summary of what you've written above.