Complex sentence: The volunteers support and listen to people who want to talk about their homosexuality or bisexuality or who are having problems with their sexuality, they go to schools to inform the high school students about being gay and to clear up certain prejudices against gay people.
Split into simpler sentences: The volunteers support and listen to people who want to talk about their homosexuality or bisexuality, or who are having problems with their sexuality. They also go to schools, to inform high-school students about being gay and to clear up certain prejudices against gay people.