Overall, there are similarities, but the movie version of Mysterio also has some differences and updates to fit the cinematic universe. For example, his motivations and backstory might have been tweaked for the big screen.
It's not a true story. Usually, such titles are imaginative creations crafted by authors or filmmakers to tell an engaging tale. The plot and characters might be inspired by various elements but not based on real events.
Spider-Man: Far From Home follows Peter Parker as he tries to enjoy a vacation but ends up facing powerful threats. There's a lot of action, humor, and emotional moments as he grows as a hero.