Look at this image (This was not made by me)
I Saw these Texture on Library, But i can’t adapt these decal (or others), these texture to a block, ever that i try it looks weird, or the texture its flipped…
How can i adapt the textures like the previous image?
This the texture 
My suggestion would be to try using the Texture object, mess around with its properties, and see if that doesn’t make the image look better. Using a decal on its own will seldom look good when placed on a random object.
Are you adding them to a Part, or a Union or a Mesh? Also when you say the Texture is flipped do you mean rotated?
If it’s just on a Part and the Texture is rotated then all you have to do is rotate the Part until the Texture is facing the correct direction and then go into the Properties window and switch the lengths of each of the axes to align with the Part’s new rotation.
If you have the Texture saved as a Decal then it’ll resize according to the Part. Textures have 2 Properties named StudsPerTile (for the 2 directions) and if you have a bunch of Parts with the same Texture applied using the same StudsPerTile value then even if the Parts are different sizes the size of the Texture stays the same.