The posters of missing children that appear in the trailer

I would like to know the order in which things will happen, because apparently the fog occurs on the current day they are on, since the 3 girls are together and if I'm not wrong Lily has the clothes from when the fog is there.

But if the fog happens today, how is it possible that there are signs of the disappearance of the 'Patty Cakes'? Since in the current episode Pennywise did not make them float