Juvenalia is probably meant to be juvenilia, the early work a writer produces while still young or still developing a craft. In poetry, it usually refers to poems written before a poet's mature style appears. Such work may be interesting for what it shows about the poet's beginnings, even when it is rough or imitative.
Example
The slim booklet gathered her juvenilia:
restless sonnets, uneven rhymes,
and flashes of the voice she would later claim.