George,
Welcome back to the Church! It is so good to have you.
What you'll want to do is make what is known as an Examination of Conscience — basically taking inventory of your sins — to prepare for your Confession. For this Confession, to keep it time-limited, focus on the serious sins you committed with full knowledge and consent (mortal sins). Given the length of time involved, you may want to write down the sins you intend to confess so you'll remember them, but of course you'll want to burn that paper afterward (or, I suppose, put it on your phone). You may also wish to make a special appointment for this Confession since, if properly done, it will take some time and may not fit into a Saturday afternoon Confession slot — unless you feel strongly about being anonymous and using the screen (as opposed to face-to-face, in which case you'll have to do it on a Saturday afternoon regular Confession schedule.)
Here is a helpful guide, produced by the U.S. Conference of Catholic Bishops, on how to go to Confession.
Feel free to ask the priest to guide you through the process of Confession if you forget at the moment or are unsure.
I think you'll feel a great burden off your shoulders when you are done!
Eric |