How do i apply a differnt textures to differnt parts of the model

Hey i have this one model that i had to convert into an FBX and all that i put it into unity and converted the images but when i put it into unity he comes out white and i can only apply one of the textures for example the body texture works but messes up the face and if i put the face on his entire body becames his face is there any way i can make my way around this please help. Thanks it would help me alot

Sounds like you want to look up UV mapping.

see - UV mapping - Unity Answers

It would seem either you have an issue with your UV maps or, most probably, the materials didn’t translate themselves properly during the conversion from one filetype to another (in this case .fbx)…
What manner of software did you use to convert your model?