I do not believe when asking a question of what is Truth or what are the Truths of the Church handed down by Jesus, the bishops or priests ever say just “trust us”. They are willing to teach and have provided us with many, many ways to learn the Truth.
We are an apostolic Church. Our faith was handed down to us by the apostles. We follow the Tradition that the Church has preserved all these years.
It is also our individual responsibility to read and study, to read the catechisms, the Bible (a Catholic bible), the encyclicals, the doctors of the Church and other saints writings and also to ask questions. There are good bishops and priests out there.
An excellent person, I think, to watch on EWTN, is Father Pacwa. He has a question and answer show and explains things very well and have never heard him just say “trust us”.
EWTN radio has many question and answer shows.
As far as Fridays and eating meat this is from the 1983 Code of Canon Law:
Canon 1250. The penitential days and times in the universal Church are every Friday of the whole year and the season of Lent.
— Canon 1251. Abstinence from eating meat or another food according to the prescriptions of the conference of bishops is to be observed on Fridays throughout the year unless ( nisi ) they are solemnities; abstinence and fast are to be observed on Ash Wednesday and on the Friday of the Passion and Death of Our Lord Jesus Christ.
*****— Canon 1253. The conference of bishops can determine more precisely the observance of fast and abstinence as well as substitute other forms of penance, especially works of charity and exercises of piety, in whole or in part, for abstinence and fast.
As someone else said, it is a discipline, not a doctrine and the conference of bishops decide.