How can I slowly leave the nest?

I’m 17 and as a teen I’ve never drank, smoked, done anything illegal, etc. I have a lot of respect for my parents. Instead of partying and hanging out with friends I do my homework, take care of my sisters and do daily chores. Recently I’ve ben talking to my mom about how I’d like to move out. She got really defensive and started talking about that I’m not ready. My intension was only to see her reaction. How do I make a boundary and let her know that I’m almost 18 and I need to get out of the house occacionally? She always puts up excuses for me not to go out. I almost feel like I need to live a double life to live like a normal person.