It appears that it was effective on the date the governor signed it, which was 2/18. It says you can sell certain non-potentially hazardous foods from your home kitchen as long as you sell directly to the consumer, and you label it appropriately. This is like an exemption, which is among the easiest ways for states to enact these types of laws; there are no rules, and it doesn't cost any money for the state. It's the ultimate form of the government getting out of our way to let us provide for ourselves.
However, there is this one little section:
(1) "Cottage food production operation" means a person who produces food items in the person's home that are not potentially hazardous foods, including without limitation:
(A) Bakery products;
(C) Fruit butter;
(E) Jellies; and
(F) Similar products specified in rules adopted by the Department of Health;
I'm not clear on (F) whether they're referring to existing rules, or new rules that are going to be written. So the safest thing to do is to call them and ask how you can comply with the new law.