This is from here at the CA Library.
catholic.com/library/Immaculate_Conception_and_Assum.asp
But what about Romans 3:23, “all have sinned”? Have all people committed actual sins? Consider a child below the age of reason. By definition he can’t sin, since sinning requires the ability to reason and the ability to intend to sin. This is indicated by Paul later in the letter to the Romans when he speaks of the time when Jacob and Esau were unborn babies as a time when they “had done nothing either good or bad” (Rom. 9:11).
We also know of another very prominent exception to the rule: Jesus (Heb. 4:15). So if Paul’s statement in Romans 3 includes an exception for the New Adam (Jesus), one may argue that an exception for the New Eve (Mary) can also be made.
Well if we believed in Scripture alone, you may have a point, even though the article claims that
you have the poor traslation from turning “full of grace” into “highly favored daughter”
But it is clear from the writings of the early church that Mary was considered free from sin.
catholic.com/library/Mary_Full_of_Grace.asp
I started in my explanation, the explanation of the Sacrament of Reconcilliation, also called Penance or Confession. The verses I referred to from the Bible show where Christ himself showed us how He wanted us to confess our sins. (John 20:21-23)
As for penance, we do something not because the work gains forgiveness for us, but because it shows we are truly sorry for what we have done.
I sense I do not understand your problem here. I came from a Evangelical background. You are more calvinist and I think there is something I just don’t get about your objections that stem from that.
In the churches I was in even before the Catholic one, they would say things like, “If you are truly sorry, that will include a desire to make things right”
Can you honestly say you are truly sorry for breaking someone’s window, truly repentent, if you don’t try in some way, to fix the damage you have done?
This too is from CA here Maybe this will help.
catholic.com/library/Forgiveness_of_Sins.asp
For sins committed after baptism, a different sacrament is needed. It has been called penance, confession, and reconciliation, each word emphasizing one of its aspects. During his life, Christ forgave sins, as in the case of the woman caught in adultery (John 8:1–11) and the woman who anointed his feet (Luke 7:48). He exercised this power in his human capacity as the Messiah or Son of man, telling us, “the Son of man has authority on earth to forgive sins” (Matt. 9:6), which is why the Gospel writer himself explains that God “had given such authority to men” (Matt. 9:8).
Good. Doesn’t make it right, and it probably happen again

, but sometimes we all get tired of explaining the same misconceptions over and over again. When* I* get tired of it, I just try to take some time off
God Bless,
Maria