If you are not a baptized Catholic then you should NOT go to the Sacrament of Reconciliation. If you are a Catholic, then you would receive the Sacrament of Reconciliation either once a year as is required or more frequentially if you are conscious of serious offenses against God. You would confess those offenses to the priest. After hearing your confession, the priest will give you some penance to perform to atone for those since and then give you absolution – wiping those sins away under the condition that you are truly sorry for them (i.e., the priest doesn’t know if you are truly sorry but God, who can see inside of your heart, does know and if you are really sorry, God removes your sins when the priest absolves you. If you are not really sorry, then your sins remain).