Following the Battle of New York, Adrian Toomes and his salvage company are contracted to clean up the city, but their operation is taken over by the Department of Damage Control (D.O.D.C.), a partnership between Tony Stark and the U.S. government. Enraged at being driven out of business, Toomes persuades his employees to keep the Chitauri technology they have already scavenged and use it to create and sell advanced weapons. Eight years later, Peter Parker is drafted into the Avengers by Stark to help with an internal dispute in Berlin, but resumes his studies at the Midtown School of Science and Technology when Stark tells him he is not yet ready to become a full Avenger.
Parker quits his school’s academic decathlon team to spend more time focusing on his crime-fighting activities as Spider-Man. One night, after preventing criminals from robbing an ATM with their advanced weapons Toomes sold them, Parker returns to his Queens apartment, where his best friend Ned discovers his secret identity. On another night, Parker comes across Toomes’ associates Jackson Brice / Shocker and Herman Schultz selling weapons to local criminal Aaron Davis. Parker saves Davis before being caught by Toomes and dropped in a lake, nearly drowning after becoming tangled in a parachute built into his suit. He is rescued by Stark, who is monitoring the Spider-Man suit he gave Parker and warns him against further involvement with the criminals. Toomes accidentally kills Brice with one of their weapons, and Schultz becomes the new Shocker.
Parker and Ned study a weapon Brice left behind, removing its power core. When a tracking device on Schultz leads to Maryland, Parker rejoins the decathlon team and accompanies them to Washington, D.C. for their national tournament. Ned and Parker disable the tracker Stark implanted in the Spider-Man suit, and unlock its advanced features. Parker tries to stop Toomes from stealing weapons from a D.O.D.C. truck, but is trapped inside, causing him to miss the decathlon tournament. When he discovers that the power core is an unstable Chitauri grenade, Parker races to the Washington Monument, where the core explodes and traps Ned and their friends in an elevator. Evading local authorities, Parker saves his friends, including his classmate and crush Liz. Returning to New York City, Parker persuades Davis to reveal Toomes’ whereabouts. Aboard the Staten Island Ferry, Parker captures Toomes’ new buyer Mac Gargan, but Toomes escapes and a malfunctioning weapon tears the ferry in half. Stark helps Parker save the passengers and confiscates his suit as punishment for his recklessness.
Parker returns to his high school life, and eventually asks Liz to go to the homecoming dance with him. On the night of the dance, Parker discovers that Toomes is Liz’s dad. Deducing Parker’s secret identity from Liz’s account about him, Toomes threatens retaliation if he continues to interfere with his plans. During the dance, Parker realizes Toomes is planning to hijack a D.O.D.C. plane transporting weapons from Avengers Tower to the team’s new headquarters, dons his old homemade Spider-Man suit, and races to Toomes’ lair. Though he is ambushed by Schultz, he defeats him with Ned’s help. At the lair, Toomes destroys the building’s support beams and leaves Parker to die. Parker escapes the rubble and intercepts the plane, steering it to crash on the beach near Coney Island. He and Toomes continue fighting, ending with Parker saving Toomes’ life after the damaged Vulture suit explodes, and leaving him for the police along with the plane’s cargo. After her father’s arrest, Liz moves away, Parker declines an invitation from Stark to join the Avengers full-time, and Stark proposes to Pepper Potts. He also returns the Spider-Man suit to Parker, who puts it on in his bedroom just as his Aunt May walks in.
In a mid-credits scene, an incarcerated Gargan approaches Toomes in prison, saying he has heard that the latter knows Spider-Man’s real identity, which Toomes denies.
Honestly Tom Holland is the best Spiderman out there. While he is introduced in Captain America: Civil War and we do see him play a role in Avengers: Infinity War and later in Avengers: Endgame, Spiderman isn’t officially an Avenger member just yet. At least not in this film. He is offered by Tony Stark at the end of the film. I think it would be great for Spiderman to become part of the Marvel Universe however with Sony owning Spiderverse, licensing gets complex right now. Disney (Marvel’s Parent company) does have some contract but they don’t have all of it ignorer to spin the plot of Spider Man 1.2.3 and The Amazing Spiderman 1&2’s plots into the Marvel Universe. It will be interesting to see how this works in the future.