Every facility is going to be different but generally be very similar.
You no longer make the rules. There will be many rules that you will be expected to follow in all different aspects. Your days will probably be very similar due to the fact they usually have some type of schedule to keep things running in an orderly fashion. Here in Oregon, incarcerated youth are able to work towards "levels" in order to obtain more privledges. Everything you do is being watched and recorded, so think twice before making a choice that you may end up regretting. Follow the rules, focus on yourself, and use this as a learning experience to change the behaviors that got you there.