Sorry if it's not a good English.I come from Germany.I did it with the Google translator.

GRASS WORLD 1-2 You go to into the first tube.

GHOST HOUSE 1 With the help of the eerie go back to Midway point,where the wall is.Makes a spin jump to the eerie up there is a hidden P.

CAVE WORLD 2-1 A hiding P is from the first Star Coin.

CAVE WORLD 2-5 Where the Joshi is, there is a hidden red shell in the near,it shoots up where P is.

CAVE WORLD 2-6 One goes into the first tube,there is a Hidden P above the tube.Go under the Blocks down there is a brown block.

DESERT WORLD 3-2 Goes to the left,in the water there is a hidden P. 

GHOST HOUSE 2 Goes through the wall to the left and there is a hidden P.

DESERT WORLD 3-3 Goes in the first tube and go left through the wall.

GRASS WORLD 4-6 Near the second Star Coin,when Mario up is.You go to the left through the wall.

GHOST HOUSE 3 Where the red Koppas are.Under the is a hidden P.

GRASS WORLD 4-9 Go left there is a hidden P,then go back up is a coin there are hidden blocks.

GRASS WORLD 4-11 Where the third Star Coin is and where ? Block are.Beside is a hidden spring board then just stay down and see a door.

SKY WORLD 5-1 Where the yellow blocks are in the middle is a invisible block a P in it.

GHOST HOUSE 5 Walks into the room,where the Midway punkt is.At the end are boxes are there you go by a invisible door is there.

ICE WORLD 6-3 Where the Buzzy Beetle are,sees one ? Block.Go to through the wall,jumps against ? Block and goes to the right there is a hidden P.

FOREST WORLD 7-3 Goes through the third tube,is there a hidden P,but you need the blue ! blocks have and sees brown SMB3 Blcke you break with a spin jump then you go back to where the first tube and the P press.

FOREST WORLD 7-4 Goes in through the first tube.Then you go in the same tube back,in which one came out after the bonus.

LAVA WORLD 8-1 Goes through the first tube you can see a coin makes  a spin jump and you get a red Joshi then feed, through the tube then with the help of Joshi tongue gets the P.

LAVA WORLD 8-2 After the door,then you go to the left through the wall and there are invisible blocks.