There's no comprehensive way to determine exactly what terms will trigger a 1st page result (as this will depend on way too many factors), but you can use various software to check whatever terms you want against the results in Google and get their positions.
Advanced Web Rankings and similar software can do this for you.
It's also important to remember that in this day and age, localisation and personalisation will significantly impact what results are shown for any given query. So you should always take that into consideration.