Elementary School in the 50's early 60's, graduated HS in '66. No, never taught about Fort Necessity in US History.
Our history books & materials were generally 'lacking'. In one Elementary school classroom the 'World map' was made just after WWI. And in HS we didn't even get to the Korean War. Book ended at WWII iirc.
[Chicago Public Schools. Good Teachers then, out of date books and materials.]
I went to Catholic grade school with very old books and public high school with new books and at that time, very good teachers as well. Washington's early life was covered in both.
If you ever get a chance to visit Fort Necessity National Battlefield, (near Uniontown PA) take it. It's worth a stop as well as a couple of other nearby historical sites -- Braddock's Grave and the Mt. Washington Tavern. Also nearby is Frank Lloyd Wright's 'Fallingwater' house.
In addition, the Heinz History Center in Pittsburgh has an excellent permanent exhibit on the French and Indian War -- A Clash of Empires. It is excellent. And beginning later this month through mid July, a traveling exhibit Discover the Real George Washington: New Views from Mount Vernon which includes many of Washington's personal possessions from Mt. Vernon. I'm looking forward to seeing that one as well.