* Geodude doesn't learn "Smash": "Smash" is a move that some Pokémon can learn through leveling up, breeding, or TM/TR. Geodude does not have access to this move.
* Geodude's movepool: Geodude can learn moves like "Rock Throw", "Tackle", "Defense Curl", and "Rollout". These moves are different from "Smash".
If you are trying to teach a different Pokémon "Smash":
* Level Up: Check if the Pokémon learns "Smash" naturally as it levels up.
* TM/TR: "Smash" may be available as a TM/TR. These can be found in various locations in the games.
* Breeding: Some Pokémon can learn moves through breeding. Check if "Smash" can be inherited.
If you have any other Pokémon moves you're trying to teach, let me know!