No cheat code turns you into Spider-Man in GTA: Vice City Stories on PS2. Rockstar never included Marvel characters, and PS2 modding is extremely limited—no script hook, no model swaps, no superhero mods.
For actual Spider-Man gameplay, play Marvel's Spider-Man (Insomniac) on PS4/PS5/PC. It's the definitive experience—web physics, combat, traversal, story. Vice City Stories is great, but it's not a superhero game.