What's an appropriate amount of put of school contact to maintain with a teacher?

I (14) have been taught by my theatre teacher for about four years now. We've always been sort of close, as close as a teacher and his good student can be I suppose. He also teaches music and over the summer he tutored me on the violin so we saw a lot of each other.

He mainly texted me showing me songs I should practice and sending me music sheets but after a while we just talked about summer and expectations for the new school year. I felt rather uncomfortable when we shifted to topics about my personal life at first since I wasn't sure if we'd get in trouble for talking or not but it's not like anyone would find out. I can't speak about it because teachers in my school are no allowed to give students extra classes.

Sometimes when we couldn't have it at my house my dad would drop me off at his place and we'd have lessons and just chill for a couple hours. I was talking to my friend about this and she thought it was really weird that he even had my number. I'm not really sure what to think