Muslim here… this is going to be a long read but I kindly ask you to read through it, as it may help answer some of your questions.
With regards Hijab, there is no writing in the Quran that specifically mentions covering hair (or any other body part except their private sections).
In the 24th Surah (Surah An-Nur) at Ayah 31, the Quran says “And tell the believing women to lower their gaze and guard their chastity, and not to reveal their adornments except what normally appears. Let them draw their veils over their chests, and not reveal their ˹hidden˺ adornments except to their husbands, their fathers, their fathers-in-law, their sons, their stepsons, their brothers, their brothers’ sons or sisters’ sons, their fellow women, those ˹bondwomen˺ in their possession, male attendants with no desire, or children who are still unaware of women’s nakedness. Let them not stomp their feet, drawing attention to their hidden adornments. Turn to Allah in repentance all together, O believers, so that you may be successful.” (Translation by Mustafa Khattab)
The idea of hijab originates from different Tafsirs (tafsirs = interpretations) of this Ayah as well as other sources, and believing in hijab is up to individuals and which viewpoint of Islam they believe.
Islam in general is a religion that promotes equality between races and genders, and Allah has said so multiple times.
If you have any other questions I’ll gladly answer.