While I admire the enthusiasm, bear in mind that not all lost media WANTS to be found. Some things are better left in the past, and sometimes there's a reason they were 'forgotten'. But, when it's about saving pieces of culture from being lost to time, I'm all in.

Your description is a mishmash of about a hundred different stock-standard YA fantasy series. Gonna need a few more specifics if you want a proper answer.