You have the tile in your inventory, right?
Go find an empty spot on Starlight Boulevard and choose to start a Ceremony.
After an amount of time, the game will say that enough Sims have arrived to watch, and after that message, you can click on the spot and choose to place your tile.
Though for the aspiration, it funnily enough doesn't have to be your own Tile.
For my Sim, I had just picked up Dirk Dreamer's Tile and placed it back, and it fulfilled the Aspiration goal, lol!