It might help to think about their titles and their real Hebrew names:
Avraham, Yitzchak and Yaakov are called “Avinu”, our father, as in Avraham Avinu, since they are the 3 forefathers. It is their names that we say in davening “G-d of our fathers, Avraham, Yitzchak and Yaakov.”
Yosef is called Yosef Hatzaddik, the righteous, since he overcame his Evil Inclination when in an immoral environment (Potiphar’s house in Egypt).
Yosef had 2 sons, Menashe and Efraim, born in Egypt. They actually took over his place as one of the 12 tribes- his tribe was split into 2, for example, for purposes of inheriting portions in the Land of Israel (each tribe’s descendants got their own portion as part of that tribe, as did Efraim and Menashe.) The names of all the descendants of the original 12 sons as they go to Egypt is listed in this week’s Parsha, each extended family is recognized as a tribe of the same name as the son of Yaakov from which they descend.
It is a great time now to catch up on these facts, since the recent and coming parshiyot that we read each shabbos in shul deal with Yosef and his brothers and sons.