Here is the full list of all 12 Back to the Future - Episode 1: It's About Time trophies - there are 7 bronze, 4 silver and 1 gold.
Heard about the curious fate of Marshall Strickland
Rescued Doc from Kid Tannen
Acquired Emmett's Rocket Drill
Flawlessly mixed up a batch of Emmett's Rocket Fuel
Delivered the subpoeana to Arthur McFly
Discovered the origin of the "new" DeLorean
Managed to get 190-proof alcohol delivered to Emmett's
Talked Emmett into completing the Rocket Drill
Namechecked BTTF Creators
Traveled back in time to rescue Doc
Got Doc's Notebook back from Biff
Perfectly repeated dialog while repeating Doc's temporal experiment