I want to be able to turn up/down volume on music and videos without affecting my ringer and notification volume, is there a way to do this?
You can separate your system sound from your notification/ringer sound under Settings -> Sounds & Haptics. Under Ringers and Alerts, toggle off "Change with Buttons." Now you will be able to turn up/down volume on your music, movies and other media without affecting the ringer/notification volume. Use the slider above the toggle to change the volume of your ringer and alerts.