What is Hh phenotype or Genotype if H=curly and h=straight?

Hh is a Genotype.

A genotype refers to the combination of alleles in an organism, while the phenotype refers to how the organism looks.

So Hh, HH, of hh are Genotypes, because its describing the alleles.

And Curly or Straight hair are Phenotypes, because it describes how the organism looks.