* No Trading: FireRed is a Generation III game, while Venusaur is a Generation I Pokemon. There is no way to trade Pokemon between these generations in the main games.
* No Events: While there may have been special events in the past, there is no way to obtain Venusaur through events in the standard FireRed game.
How to get Bulbasaur (Venusaur's pre-evolution):
1. Start with Bulbasaur: At the beginning of the game, you have the choice to pick Bulbasaur, Charmander, or Squirtle. Choose Bulbasaur.
2. Level Up: Level up Bulbasaur to level 16 to evolve it into Ivysaur.
3. Level Up Further: Level up Ivysaur to level 32 to evolve it into Venusaur.
Possible workarounds:
* Gen I Emulators: You could play a Gen I game like Red or Blue on an emulator, catch Bulbasaur, and level it up.
* ROM Hacks: Some ROM hacks of FireRed may allow you to obtain Venusaur, but they are not part of the original game.
Let me know if you have any other Pokemon questions!