I heard that only the bishop can only absolve certain sins. So that may mean that I need to go to a bishop to confession. Does anyone have a list of sins that only a bishop can absolve?
For and Eastern Catholic there are still reserved sins and the only penalties are
ferendae sententiae, but for a Latin Catholic there are reserved penalties, such as
latae sententiae excommunication.
Most reserved penalties can be lifted by the local bishop, but some are reserved to the pope, such as
latae sententiae excommunication reserved to the Apostolic See. Others could life them by indult or delegation. Five are reserved to the Apostolic See.
In the danger of death, see CIC 976 below (also for Eastern Catholics CCEO 725):
Canon 976 Even though a priest lacks the faculty to hear confessions, he absolves validly and licitly any penitents whatsoever in danger of death from any censures and sins, even if an approved priest is present.
Canon 725 Any priest can validly and licitly absolve any penitent in danger of death from any sin, even if there is present a priest endowed with the faculty of administering the sacrament of penance.
Canon 1364 - An apostate from the faith, a heretic, or a schismatic incurs a latae sententiae excommunication.
Canon 1367 - A person who throws away consecrated species, or takes (or retains) them for a sacrilegious purpose, incurs a latae sententiae excommunication reserved to the apostolic see.
Canon 1370 - A person who uses physical force against the Roman pontiff incurs a latae sententiae excommunication reserved to the apostolic see.
Canon 1378 - A priest who acts against the prescript of Canon 977 incurs a latae sententiae excommunication reserved to the apostolic see.
Canon 1382 - A bishop who consecrates a bishop without a pontifical mandate, and the person who receives the consecration, incur a latae sententiae excommunication reserved to the apostolic see.
Canon 1388 - A confessor who directly violates the sacramental seal incurs a latae sententiae excommunication reserved to the apostolic see.
Canon 1398 - A person who procures a completed abortion incurs a latae sententiae excommunication.