Talk to Blathers after donating 5 creatures to the museum
Receive the shovel recipe from Blathers
Craft a Flimsy Shovel at a DIY workbench using 5 softwood
Buy the Shovel from Nook’s Cranny once it is available
In New Horizons, use the shovel to dig up buried items and fossils
In older Animal Crossing games, obtain the shovel from Tom Nook’s shop or special characters depending on the version