Many people don’t go to the Sacrament of Reconciliation simply because they don’t know what to do and are afraid they’ll be embarrassed in front of the priest. Don’t worry, this puts you in the majority of Catholics, not the minority!
Priests are very familiar with individuals coming to them and saying “Father, I have no idea what I’m supposed to do, can you help me?” The process is below, but if you can’t remember, don’t worry. The priest will be happy to walk you through the steps.
First greet the priest and say “Forgive me, Father, for I have sinned, my last confession was…” and tell the priest when you last went to confession. Then simply confess your sins.
The priest will likely ask if you have any others to confess and he may offer you some advice on how to avoid those sins in the future. The priest will then give you a penance, often a set of prayers, but it is up to the priest what to give. Penance is NOT a punishment. Penance is a way for a person to strengthen the weakness that lead them to sin in the first place. It helps us resist committing the same sins again.
After this you will be asked to make an act of contrition. There are formal prayers out there and most confessionals have such a prayer written on a card for you to read. Otherwise simply saying something like “Jesus I am truly sorry for my sins. Please help me not to repeat them” is perfectly acceptable.
After this, the priest will absolve you of your sins and that is an amazing feeling!