look on your map
route 111
The earliest route you can get it at is Route 4.
route 3or4
route 23
Route 6.
Route 225 is not a route that can be found in Pokemon Firered, route 225 is in Pokemon Diamond, Pearl, and Platinum. To get there is Diamond Pearl and Platinum, you have to see every Pokemon in Sinnoh, then talk to Prof. Rowan and get the national dex.
Route 111
route f
You can trade an Abra for Mr. Mime in a house on Route 3 in Pokemon FireRed.
Route 111 (Desert)
pidgy and rattata
Route 11 is just east of Vermilion City.