'Interesting in shoujo terms means that they will probably or are in love with you. But since he's your dad and this is a manhwa, he actually means that you will end up doing big things in the future. Another possibility is that he just thinks you're fucking weird. Lecture done.
Gosh I really like this manhwa. The MC, even though she has time travelled, really act and think like an actual child. A really cute child at that. This is really refreshing to read~