Asking a question is usually what the first step is.
You did not provide an image for me, but I can explain.
Homozygous, with the root homo, means same. Therefore, a guinea pig parent with homozygous traits would have the traits being the same - either both recessive or both dominant, ie TT, tt.
Heterozygous on the other hand means different, therefore the traits would be one dominant and one recessive - for example, Tt.
If for the punnet square it has different traits (Combo RB for red and black or combo RW red white for like fur color) than heterozygous would be any that isn’t like TT or tt or any other letters used.
Hope this helps!
