Stirching textures together to make another one

Hi everyone. So I have been working on a project recently and I've just started working on the terrain generation. I've made a Perlin noise script to find out what should go where. but now I have the issue. I want to put together textures (may be about 16x16 pixels) based off the Perlin noise map made. Then apply the texture to something. This could be a large plane. So do you know how i could stitch the textures together?

Thanks. Callum