this is my guess after you get the lost item go out the door and steven will talk to you!
Get a rotom
You can't.
there is no silph co in that game
no you will not meet Gary at the Silph Co. you will be battling Giovanni there.
On the 5th floor of silph co.
Get a rotom
You can't.
Silph co is in saffron city.
there is no silph co in that game
In order to activate the Silph Co. elevator, you need a Rotom traded from Pokémon Diamond, Pearl or Platinum, from breeding or from cheating via an Action replay and you also have to put it as the lead in your party in order to power it up so you can go to the next floor in order to change Rotom's forms.
you get it in silph co
no you will not meet Gary at the Silph Co. you will be battling Giovanni there.
Sabrina is not in silph co she's in the gym.
You have to go to Silph Co in Pokemon LeafGreen. You have to go there to get the Silph scope, which you need to advance.
The silph scope is not in silph co its in the game corner.
On the 5th floor of silph co.
you defeat Pokemon trainer red and then he comes to silph co