8 Spider-Man: Homecoming Plot Spoilers We Already Know
1. Peter Parker Makes A Bad Situation Worse
This is becoming a bit of a trope as far as Marvel's movies are concerned and, from what information they have released so far, it doesn't look like Homecoming is about to break any new ground. Basically, Spider-Man's actions will put the people he cares about in danger.
The turning point in the trailer's tone comes when Peter proclaims that he now has a chance to prove himself. After these famous last words, the music shifts from the dulcet tones of MGMT to an ominous barrage of noise, everything starts exploding and the lion's share of screen time is then dedicated to Keaton's Vulture.
The clear implication is that Peter hasn't listened to Tony's warnings about staying away and has baited the Vulture from his crime spree to indulge in some destructive vengeance. It's not like Toomes doesn't explicitly say that he will go after everyone his adversary cares about if he isn't left alone.
His actions will mirror Tony Stark's creation of Ultron, with him trying to solve a problem but actually making the situation so much worse.
Be prepared for Spidey to learn this lessons the hard way and end up needing Iron Man to swoop in for an explosive final battle that will allow Marvel to make the most of their bottomless special effects budget.