Welcome back to the Church!
Since this will be a confession covering many years, consider making an appointment rather than getting in line during the regularly scheduled confessions as it may take a while.
I would encourage you to follow the very simple guide provided by tcraig. Here are a few other versions.
cin.org/avatar/examcon.html
therealpresence.org/archives/Sacraments/Sacraments_005.htm
scborromeo.org/confess.htm
This site has a series of links to various forms of examination of conscience.
geocities.com/Heartland/Estates/4152/exam.htm
When I converted I had to make a general confession that covered more than 30 years of my life. Let me tell you what I did.
I bought a small notebook and a pen. I used a couple different “examination of conscience” references and began writing down my sins, organized in the same way as the examination of conscience form was. Then I reorganized this list into chronological order, adding any sins I had overlooked the first time. Then I reorganized the list again by type of sin, again adding any sins I overlooked the other two times. By the time I was finished with this second reorganization, I felt I had a fairly complete list. I took the list to my confession and went through it with the priest. Afterwards, I burned the entire notebook and the pen I had used. I sprinkled the ashes with holy water and buried them.
This effort, which took a couple of days, had a profound effect on me. It really made me conscious of my faults and my desire to rectify my life. While it sounds painful, it was one of the best things I ever did!
Imagine how wonderful it will be for you to be able to receive the precious Body and Blood of our Lord in Holy Communion after you make your confession. May God bless you!
