hey,

i recently learned how to operate a boeing 777's FMS and did a tutorial flight but there is one thing that i still dont understand, how do u find out what all the LEGS are and stuff?

That info would be on the flight plan also referred to as the flight plan release. The FPR would list each waypoint (entered while stringing the flight), estimated time between that waypoint and the next one, mag course, distance, etc.