Jokes can be good, jokes can be bad.
Don't do something you will regret tomorrow.
Stay lighthearted and innocent with your jokes. Something like rearranging the items on your coworker's desk. A woopie cushion under a pillow. A fake mouse under a blanket.
The second you try to be funny with fake promises like game DLCs or announcements like marriages/divorces or promotions or babies; you risk breaking hearts and ruining the mental states of others.
If you would be highly displeased if somebody did it to you, do not do it to anyone else.
Here are some of the good jokes you could play on the people in your life;
1. Hide two things, but tell them you hid three things
2. Replace your family photos with photos of somebody else
3. Text them a GIF of the "typing" dots
4. Put some plastic on the top of their shampoo bottle, then screw the top back on
5. Put sugar in their salt shaker
6. Put balloons in their office or bedroom
7. Tape something to the bottom of their computer mouse, rendering it temporarily unusable
8. Place a fake snake in their belongings
9. Hide behind a door and scare them
10. Swap their hand sanitizer with glue