Set-up IOHK binary caches How to set up the IOHK binary caches. "If you do not do this, you will end up building GHC, which takes several hours. If you find yourself building GHC, STOP and fix the cache."
Enter a nix-shell.
Go to the plutus-playground-client folder.
Start the Playground server with plutus-playground-server.
Start the Playground client (in another nix-shell) with npm run start.
Copy-paste the auction contract into the Playground editor - don't forget to remove the module header!