Catch up with all that stuff you wanted to see
Legally of course.
Play all those videogames you never finished.
Check those albums from your favorite bands you never listened.
If you code, do a personal project since you are at home and it will be hard to prove you did so during working hours. Use a different machine to do so just in case.
Make sure the kids are getting those fancy smarty online classes, instead of slacking off and saying they are.
Don't panic and carry a clean towel, the rest of your family are going to get most towels dirty.
If you plan on cooking but is something you don't do regularly, focus on the darn recipe.
Don't worry about the video data caps on video resolution, you need a TV the size of a Cinema screen to notice the difference anyway.
If you dabble with hardware; get Raspberry Pi on the cheap and do a project with it. Before you notice it will be a month already.