Route 11 is mostly grass and Pokémon trainers. There are 10 trainers waiting to battle you. Fortunately, their skill in very developed so you ought to have no trouble getting through. Above the building is one of Professor Oak's Aides who, if you have 30 Pokémon. will give you the Item Finder which will locate hidden items. When you exit the building to Route 12 you'll see that a Snorlax is blocking your path so you'll have to head back to Cerulean City. Once there if you go through the Robbed House and then go East instead of going South you'll be on your way to Route 9.
