We’re in Ireland where schools have closed now. Mine are primary age, and will be getting school work sent from Wednesday. I’ve made it clear that we will be doing homeschooling and that they are responsible for setting their own hours, and working out a timetable. We had a trial run on Friday and it went well.
We have a science experiment book and mister maker art book that they can pick and choose from.
I’ve raided the library for books.
We can do yoga, dance, karate from you tube. There’s basketball, moonball, trampoline or an obstacle course for the back garden.
I’m making them keep a diary for posterity 
I’m also encouraging them to engage with the curricular material they’re sent in ways that interest them (eg when ds is inspired to build a ship in Lego or Minecraft after reading about Christopher Columbus, I’m going to run with that)
I’m encouraging them to take on a project or challenge that interests them.
I keep a decent craft box, pens, pencils, colours, paint, glue, tape and lots of blank paper.
I’m also teaching them, sadly neglected, household skills like cooking, cleaning etc because they may need them in the near future.
I think it’s going to be important for morale to keep up a routine in the next while, insist on getting dressed in the morning, etc., and keeping a separation between weekdays and weekends.
With younger dc, I strongly recommend setting up an “invitation to play” which is basically just setting out an activity or task that they can find waiting for them. For some reason it sucks them right in, whereas if you are there suggesting it or setting it up with them, they’re not that interested.
Sensory activities (play dough,rice box, sand, water) are very calming and can give you a bit of a breather between activities that require more input from you.
If you’re not used to entertaining smaller children all day it helps to plan backwards from the clean up. Spread out a big sheet on the floor before rice play. Gather up towels and other laundry for soakage during water play. The bath is an excellent location for painting!
Pinterest, if you can avoid getting sucked into the perfectionism, is a great source of ideas if you search for homeschool, summer projects, etc
There’s some links and reviews to apps that may be useful.