I’m going to preface my response by saying that I rejoice in your commitment to the teachings of the Church, and I think that in general, we would probably agree on many issues. Also, it is quite possible that your speaking style is more charitable than your writing style, but I can only go by what I can see.
To OP…I’m very sad to say that you will find majority of Catholics today in the U.S. do not follow most of the teachings of the CCC, these are called “Cafeteria Catholics” or “lukewarm” Catholics. I too have only been with the Church for a short time (6 years) and have also been astonished at the lack of instruction from RCIA or even those around me that consider themselves to be faithful Catholics.
I think you need to cut people some slack. For at least 20 years (possibly more like 30), starting about 40 years ago, catechesis was frequently poor. People who were raised in that time don’t necessarily know they are missing something. If you go up to them and call them lukewarm and Cafeteria Catholics and so forth for not following teachings they were unaware of, they will not listen to you because you have offended them. Assuming that people are doing the best they know is required of you by charity, until you have actual evidence to the contrary.
Keep in mind that some priests have made the problem worse, by saying things in homilies that aren’t in accordance with the teachings of the Church (e.g. regarding artifical birth control), or by omitting to say things that are teachings of the Church, for fear of offending people.
In any case, I’m pretty sure that saying that the majority of US Catholics don’t follow most of the teachings of the Church, is probably wrong, unless you are including baptized Catholics who have fallen away from the Church.
The bottom line is…any many will disagree with this comment…to be a faithful Catholic, we are called to follow everything in the Magisterium (not just the things we like or agree with).
In fact, I think most (not all) of the Catholics on this forum would agree with this statement. I certainly do. Included in the teachings of the Church that I follow is the one that says “Unintentional ignorance can diminish or even remove the imputability of a grave offense…” (CCC#1860)
Your best bet in becoming a faithful Catholic is to start your journey with familiarizing yourself with the Catechism of the Catholic Church and following it in your everyday life and reading the Gospels every day to get to know Jesus better and attend Mass as frequently as you can in addition to Sundays.
This is great advice.
Also, do not be afraid to educate the “cafeteria Catholics” to either inform them of what they weren’t taught or to speak against their misaligned notions of what constitutes a faithful Catholic.
This is less great advice. There is a lack of charity in assuming that everyone who doesn’t know everything is a “Cafeteria Catholic” that really needs to be fixed before the information you give is likely to help people.
For example, when I was growing up, this new Catechism didn’t exist. I never heard even of the Baltimore Catechism until I was an adult, because it was considered too old-fashioned to teach from, I guess. Had I been unfortunate enough to be somewhere where the Catechism isn’t mentioned at Mass, and/or had I never left the Church, I wouldn’t know that I needed to read it.
If a convert (or anyone else) came up to me to “educate” me, with a manner that shows that she considers herself “faithful” and me only a “cafeteria Catholic,” and mentioned the Catechism, it would only be likely to make me not want to read it.
I have been greatly blessed with knowledge. I have personally read the entire Catechism, and most parts of it more than once. I have read the entire Bible several times. I follow all of the teachings of the Church that I am aware of. I also assume that for people who don’t do so, it is either because they don’t understand, or don’t know of the teachings. Sometimes they say they know of them and understand them and just disagree, and then I might think of them as “Cafeteria Catholics.”

But unless they say so, I have to give them the benefit of the doubt.
"Respect for the reputation of persons forbids every attitude and word likely to cause them unjust injury. He becomes guilty:
- of rash judgment who, even tacitly, assumes as true, without sufficient foundation, the moral fault of a neighbor;… " (CCC #2477)
Willful ignorance is no excuse for any Catholic because we all have the ability to read the CCC regularly, and not just when we need to find an answer.
Of course, if they are ignorant of the need to do so…
However, I don’t think the thing about doing penance on every Friday is even in the Catechism. I think it’s in the Code of Canon Law, which nobody expects every Catholic to read. And it makes sense that it is there because the Catechism is supposed to be universal, and the exact requirements for Fridays are only a discipline of the Latin Rite.
All the Catechism has is, “The seasons and days of penance in the course of the liturgical year (Lent, and each Friday in memory of the death of the Lord) are intense moments of the Church’s penitential practice. These times are particularly appropriate for spiritual exercises, penitential liturgies, pilgrimages as signs of penance, voluntary self-denial such as fasting and almsgiving, and fraternal sharing (charitable and missionary works).” (CCC #1438)
A person could be excused if they had read that and didn’t realize it indicated any specific obligation.
–Jen