How to persuade my parents

Let me paint a picture of my situation. I'm a full ledge adult now but asking permission to go out is so fucking difficult. Even asking to go to my friend house 1km from my house. In comparison my school is also 1km from my house and I walked there by foot. Sometimes I lied (yeah I fucking lied) I went this near but actually I went a little bit further. I think my parents doesn't really care about me going out with a partner since I acted like Idgaf about love (I do have romantic feeling lol) ok enough of that.

This May/June, there's a book fair in my country, capital city. I think around 360km from my house. I... I rashly without consulting my parents, excitedly promise my long distance friend, we would go to the book fair together we planned to go there using train. (She used to train so I don't mind) Money... I also don't mind since I can earn it. I mean the book fair is far later. We'll stay there for 2/3 days only ...2k dollar is enough right? I don't live extravaganza and I'm okay with not eating dinner also it's not like I'll go to attraction places.

Aaaaaa got distracted, anyway my parents doesn't really like that friend... More like family problem. My parents is jealous with my friend bcs whenever she invited me to go somewhere with her, I'll go. On the other hand, my parents always said, invite her to our family gathering. And I said no.. I can't bear to see them judging her. My other friend once got crushed by my parents so I don't want that to happen again. Not on my watch! AAAAAAAAA DISTRACTED 2.0 I just want to ask how to persuade them so that I can go to the book fair that is 360km far with my friend that they don't really like?