Now that the group is decided on I'm all confused what to do with it like, I'm supposed to be able to pick a favourite here? And what now?

This is why girl groups usually have 'supporting members', like the level of this group is so nuts. It has about 57 members who could be the visual, the dancer, the rapper, the main vocal, or just a generally super charismatic performer. Nobody is the "weak link" here, and certainly not Sohye even if she lacks in skills.
So I'll just wait it out for now!