Using materials to make a texture (PNG)?

So I have had no luck figuring out how to texture my models, but I have been able to make materials work (ish). However my understanding is iof I export a model, its will export any materials as a mtl. Now the program I am making models for only uses textures (aka pngs). Is there a way to convert the materials to a texture, or am I just talking about stuff I have no clue about again?

You can bake the object material colours to a texture with render baking https://www.blender.org/manual/render/workflows/bake.html

You will first have to UV unwrap the object to control how the texture is mapped to the object.