After you complete graded assignments in a course, your score will appear on the Progress tab. There you will find a graph of all graded assignments in the course and below that, a list of all assignments and their scores.
Only graded assignments will appear on the graph and count towards your final score. Ungraded "practice" assignments will not show a score.
The "average" columns show your cumulative average for all assignments of that type through your course. This will rise as you complete more assignments of that type.
To pass you will need a Total score meeting or exceeding the "Pass" line between the gray and white sections on the graph by the course end date.