SSE making new ground types?

[Majormonologue]

I have just gotten the creation kit after modding some on the original skyrim, my first mod project is to make a custom home in a tropical island chain, or something with a tropical island to change the cold feel of skyrim, though I am a noob modder I thought it would be a good idea, but I have no idea how to make a sand ground texture! If anyone can help that would be appriciated