My 19mo toddler is going full day childcare soon. Is there anything I should take note of? Should I accompany her whole day on her 1st day?

Personally I feel yes you should stay to observe how the school do their daily activities. I am glad I stayed the first day with my son and withdrawed after a week. Whatever you do, please remember to assure your child you will be back and not just sneak away. Yes they will get used to it but you need to use the softest and gentlest approach.