Powerless, by Matthew Cody
From Google Books:
Superheroes soar in this promising debut—and they’re kids!
Twelve-year-old Daniel, the new kid in town, soon learns the truth about his nice—but odd—new friends: one can fly, another can turn invisible, yet another controls electricity. Incredible. The superkids use their powers to secretly do good in ...
This is wildbow's Worm series.
An introverted teenage girl with an unconventional superpower, Taylor goes out in costume to find escape from a deeply unhappy and frustrated civilian life. Her first attempt at taking down a supervillain sees her mistaken for one, thrusting her into the midst of the local ‘cape’ scene’s politics, unwritten rules, and ...
Looks like that is supposed to be Captain Marvel/Shazam from DC:
Click image to enlarge.
More specifically this is Shazam from the Injustice: Gods Among Us game and the "Injustice: Earth One" universe. You can compare to the video below found by @Valorum: