Here is the interesting thing.
What do you open up? Businesses, if you have a children, where do they go? Remember, most high school students use mass transit, at the elementary levels, do you really think teachers in NYC want to be exposed to the potential risk?
Since you asked, if I was king for a day I'd do the following:
Keep schools closed since there is a reasonable, working alternative. Keep youth and HS sports shut down for another couple months.
Shut down mass transit, including all subways, trains and busses (you too NYC).
Keep high-touch businesses closed - gyms, hair salons, massage, etc.
Let businesses that can operate go ahead and do so, considering that many won't have lower level employees able to show up. If you can work remotely, then you should work remotely. Many in finance, banking/trading, accounting, high-tech, news, publishing, advertising, consulting, etc can do this.
Let retail open up a limited capacity. Let each business determine safety codes, number of customers, etc. By the way, many retailers have been open so this is evidence that it is ok to do so.
Let manufacturers that can open up do so. Let each business/union determine safety rules.
Open up parks, beaches, hiking/jogging/cycling trails. It's April after all, not August.
I would keep Hollywood shut down indefinitely.