[curt.clifton]

The Filter bar is now called the View bar. Turn it on; you'll need it. In the view bar, set it to show only Remaining tasks in Project View. Then the completed actions will go away.

You really need to learn how to find your way about the various views before investing much time in other features of the program. Experiment with both Project and Context views and with the various view bar settings. If you find a combination you like, you can save it as a perspective so you can easily come back to those settings. Don't worry about getting your perspectives exactly right at first though, just save the combinations of view settings that seem useful to you.

Good luck!