Everyday Julia goes to study. Why it is wrong?
I think because if har din comes at the beginning then what your saying is correct but if it comes after the noun then its wrong
Does this mean julia goes (somewhere) to study or is it another way of saying julia studies every day?
Why does the verb infinitive get pluralized?
It's not being pluralised. We are using the oblique form of the infinitive. This is because it is the object of an intransitive verb (जाना).
Is this a strange sentence? Or does it mean something like she goes to the library to study - can't quite place the 'goes'.
It means something like that, yes. She goes to the school, a library or even her room everyday to study.