I don't know much about phenotypes, but as far as inherited traits, I can give you a suggestion!
Check out the research by Gregor Mendel done on pea plants and inherited traits. It talks about dominant genes (example - dark hair) and recessive genes (light colored hair) and how people can carry a recessive gene with a dominant trait. A Punnett square is one of the simplest ways to track traits.
This is a decent link to look at
https://www.sciencelearn.org.nz/resourc ... nheritanceBut try using these lines to search for additional information on google:
gregor mendel pea plants
pea plant traits dominant and recessive
Punnett square
punnett square calculator
Good luck on the research!