I believe the federal standards for group homes is that they must provide you with security for your bedroom if you request it. Your room can be locked when you are in it and when you leave. However, you are likely to have a roommate, who would also have a key. And group home staff would have a key. This last seems invasive, but it is really a safety issue. I do know someone who died choking in his room and no one could get in to help him.
Before you go to a group home, make sure you know their policy on residents being allowed to have locked doors. Because even though it is a right, many homes disregard it.
There may be some better options than a group home, depending on what state you are in. Some people live in supported living situations with live-in or daily help in the home. These provide safety and assistance without so much restriction on your own personal preferences and lifestyle.
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The river is the melody
And sky is the refrain - Gordon Lightfoot