Revolutions typically start by the voice of one person drawing attention to the need for a change. People then join in with the idea and move forward in united action. In the case of a good revolution this will look like securing freedom, liberty and access to natural rights for an oppressed population. In a bad revolution this will look like a subset of the population looking to vaunt itself and introduce oppression to others. Good revolutions result in more freedom for the majority. Bad revolutions result in less freedom for the majority.
Good revolutions require awareness and education for the oppressed group in order for them to understand their oppressed state and obtain the necessary skills and abilities to conduct the revolution and overthrow the oppressors. Bad revolutions seek the opposite: make the people ignorant, keep them ignorant and remove anything they might have in order to defend themselves, physical, emotional or intellectual. An ignorant population is easier to control, especially if unarmed and unsure.
Animal Farm (1945), by George Orwell, is a remarkable example set in a fictional story of how revolutions work, both good and bad. Essentially, the book relates the idea that a good revolution can quickly turn sour, or what seems like a good revolution at first may actually only be a front for the underlying current of evil that is actually moving the effort along. The book is easy to read and not very long, I encourage everyone to read it. Even if you read it in high school and think you remember it, read it again. You will see these elements of good and bad revolutions in it. You will see the use of propaganda. You will see that the elements of total control are never very far from any governing body. If you don't like reading, you can watch a cartoon version for free on YouTube.
We all need to stay informed, gain all the education we can and voice our concerns. There is no need for violent revolution. Good revolution can come in the form of changing policies and attitudes and all without anyone getting physically hurt.
Watch this video about some recent news items regarding schools and gun control. Even if you don't like the commentator, just watch and listen. If you really don't like him, pretend he is Ralphie from A Christmas Story, he is all grown up and now has a satirical news/history commentary show.