After a few hours you will see a view similar to the one on the image.
Notice how the timelines are now filled with data.

• Computer usage timeline shows your active and away(idle) time
• Application timeline shows which application was used, when and for how long. Each application is presented in its own color so you can easily see when you started or stopped using it.
  ManicTime tracks only currently used window, so even if you have ten applications running at the same time, it will only track the one you are using at the moment.
• Documents timeline shows you which sites you visited and which documents you opened.

If you move your mouse over timelines, a hint will pop up showing you more information about underlying activity, so you can easily see which application you were using at that time.

ManicTime will track all of this data automatically and you don't need to do anything else.