Where I can find Mr. Fuji

Mr. Fuji is at the top of Pokemon Tower in Lavender Town.

You won't be able to get to the top of Pokemon Tower until you have the Silph Scope. You will obtain the Silph Scope after you defeat Team Rocket in their hideout found within the Celadon City Game Corner.

Hope this helps!

You need to defeat Team Rocket in Silph Co.first. Once you have the Silph scope from them you can use it to get past the ghost in Lavender tower and after beating 3 rocket grunts you can speak to him.

To get to Mr. Fuji, you have to get the silph scope. To get the silph scope, you have to go to the Game Corner in Celadon City. Just talk to the Team Rocket member standing by a poster on the north side of the building, and he will battle you. Then, when you defeat him, press the button on the poster and a staircase will appear if you go east. Once you go through the basement, you will eventually get to their boss, Giovanni. You will have to battle him, and once you beat him he will leave behind the silph scope by the couch. Then you go to Lavender Town and go to the top of the Pokemon Tower. (keep in mind that your Rival will be near the entrance) Go to the top, and when the ghost appears, you will automatically use the silph scope, and find out it was a marowak. Then you go up the stairs and battle the three team rocket grunts, and then you can get to mr. Fuji. :D