Do childcares provide food for kids at 18mths? What if the kid is allergic or refuses to eat certain food? Can we bring our own food? Also, at 18mths, do the teachers feed the kids or do the kids have to feed themselves?

Yes, you can bring your own food if you do not want them to eat whatever the school is providing. I have a cousin who's paranoid about the food the school was serving because she doesn't know what goes into making it so everyday she wakes up early just to prepare lunch box for her child. It's your child, so it's your say. The school cannot tell you what your child can or cannot eat