The character wears a costume bearing an American flag motif, and he utilizes a nearly indestructible shield which he throws as a projectile. Captain America is the alter ego of Steve Rogers, a frail young man enhanced to the peak of human perfection by an experimental serum to aid the United States government's efforts in World War II. Near the end of the war, he was trapped in ice and survived in suspended animation until he was revived in the present day. Although Captain America often struggles to maintain his ideals as a man out of his time with its modern realities, he remains a highly respected figure in his community which includes becoming the long-time leader of the Avengers.

Source: Wikipedia

Be Like Steve:

Scarlett Johansson portrays the character Black Widow (Natasha Romanoff) in films Iron Man 2, The Avengers, Captain America: The Winter Soldier, Avengers: Age of Ultron, Captain America: Civil War, Avengers: Infinity War, Captain Marvel, and Avengers: Endgame as part of the Marvel Cinematic Universe. Johansson will also star in her own Black Widow solo film.

Characteristics:
Black Widow is a human, trained in the arts of espionage and martial arts, with specialities in hand-to-hand combat and interrogation. She has the athletic prowess of an Olympic class athlete and appears nearly superhuman at times

The character's in-universe backstory and parentage has been changed more than once. Depicted in the 1970s as the children of golden age superhero Whizzer, a retcon in the 1980s revealed Scarlet Witch and Quicksilver to be the unknown offspring of supervillain Magneto. Born to Magneto's estranged wife in Transia, Scarlet Witch and her brother are left in the care of their adoptive Romani parents and she is raised as Wanda Maximoff (later referred to as Wanda Frank while the Whizzer was considered to be her father). In another retcon in the 2010s, it is revealed that Quicksilver and she are not mutants but were kidnapped and used as subjects of genetic experimentation by the High Evolutionary, then misled to believe Magneto was their father.

Characteristics:
Scarlet Witch is depicted as calm and submissive, as with most female comic book characters of the time.