Good timing! I think Bluesky will be the place to be for kidlit illustrators, it seems to be one of the few platforms that don't work against artists. I even saw an art director at Scholastic (Brian LaRossa) that offered a free portfolio review/coaching session for a randomly selected person in a thread here.
Cara is in its infancy and isn't really in a useful state right now β it still boosts the already established illustration giants, hash tags show limited results; basically agents aren't going to find you there either. I think it's wise to 'save your name' there for now but I don't really see it having a utility as yet. The heart is in the right place though.