u can start really generally, eg. i tend to take revenge on people (the prawns incident) instead of forgiving them, i tend to lie when i am scared and i love hearing juicy gossip so i can feel proud that i am better than other people. (just making up some examples.)
then the priest can say if he needs more details.
i am surprised someone said confession may take 5 - 10 mins, mine has never been that short!
maybe i am rli bad!
in some churches is there a little room u go into?
in our church people confess at the back of the church when everyone has gone out of the church.
so we can see them but we can't hear them.
if u r embarrassed for others to see u weeping tears of repentance and getting emotional (i am only half joking!) u can ask to go somewhere more private.
confession makes more sense after someone has been baptised, then the 'bad' things feel more bad and the 'good' things more good. yr conscience gets a clean-up and works much better after you are 'born again' through baptism.
u keep the conscience clean and working by regular Holy Communion and confession.
also people should repent their sins to God, it's best to do that while praying before u go to confession, so that everything is open before God.