Welcome!
As others have said, the priest and/or those who will assist in RCIA (presuming that’s the path you are on) will help you with this. As the RCIA guy at my parish, I will share with you what I share with my people. I don’t mean to be long-winded, but I’m building to a point (or perhaps several points).
There are two primary classifications of sin: mortal sin and venial sin. Mortal sin cuts off our relationship with God while venial sin damages it without rupturing it completely. In other words, venial sins bend the stick while mortal sins break it.
For a sin to be mortal, it must fulfill all three of the following: (1) it must be grave, serious matter; (2) it must be something done with full knowledge of the sinfulness of the act; and (3) it must have been chosen freely with complete consent. If any of these three characteristics is missing, the sin is venial, not mortal.
In Confession, we have the opportunity to be forgiven of our sins, both mortal and venial. It is
required that we confess all
mortal sins. Not only must we confess them, but we must also confess the number of times we committed them. Strictly speaking, we do not have to confess venial sins, but it is nonetheless a good thing to do (because the sacrament gives us grace and can help us to commit even venial sins less often).
Now, this can seem quite intimidating to many, but we must recall that our God is a merciful God and the Church is a merciful mother. The Church does not obligate us to do what is impossible. Very few of us have photographic memories with perfect recall. Particularly for those like yourself who will be confessing for the first time, it is unlikely you will remember the number of times you committed every grave sin. The priest, too, understands this. The important thing is to do your best and not deliberately withhold something.
Now, in many cases, the priest does not need to know (nor does he want to know!) the minutiae of every sin. But, sometimes, details are important. Saying “I was angry and I hit someone” is one thing. If that person was your elderly mother, that would be a detail you need to include because it changes things.
You mention the bullying. Now, the priest may not need to know the specifics. But if he asks a question asking for more details, answer it honestly. And if you think the details are important, ask the priest about it.
Confession can be intimidating, but I think there can be great grace in embracing the uncomfortableness of it. Sin isn’t pleasant. We can’t whitewash it and pretend it’s okay. Sometimes, boldly naming and confronting it, even though it is a major exercise in humility, is exactly what we need to do.
And always remember, the priest has heard it all before and is bound by penalty of excommunication not to ever reveal anything about your Confession. I’ve never known a priest who does not take that absolute secrecy
very seriously. They would sooner be tortured and die rather than reveal to someone else what you told them in Confession. So whatever you tell the priest, it will remain private.
God bless you on your journey!
