If you want to create an easy ladder.

If you want to create an easy ladder then you can just go to

Textures->Usage->Tools->Ladder Der Lad.

Once you have found "Ladder Der Lad" then you can now make an easy ladder.

To Build the acual platform of the ladder like  a ladder shape.

to build this, you can either build the shape yourself. Or you can read a different tutorial on how to find that ladder.

Tutorial Made By Ploxxy.