So if this is supposed to be the story of the Buzz Lightyear that inspired the toy line within the Toy Story universe, based on what I see from the trailer, this is how I'm guessing the story will go:
1) Lightyear isn't his real last name, but a nickname he gets because he's testing faster than light travel on Earth
2) He'll break the speed of light and end up in another part of the galaxy, and meet Star Command
3) When he gives his name as Buzz "Lightyear," that will become his name in Star Command
4) All the spaceflight tech is not from Earth, but Star Command, in fact most of the footage looks like it's from his time with Star Command
5) Fights some of Zerg's army/meat of the story
6) Returns to Earth
7) Tells his story to NASA, be deemed crazy
8) Decides to return to Star Command
9) Friend from Earth will tell him that he'll make sure Buzz's story is remembered (why there's an in universe TV show and toys)
10) Buzz goes back to Star Command. Tells his friend he's going "To Infinity and Beyond!"
Opens possibility for sequels where Buzz fights Zerg
Not sure if I'm warm to the idea of alien empires and intergalactic space warfare in the Toy Story universe (which essentially has magic), but I'm still interested