-The Catechism of the Catholic Church
-Theology for Beginners by Frank Sheed
-Theology and Sanity and Frank Sheed
**-Fundamentals of Catholic Dogma by Ludwig Ott **(This one may be a bit too esoteric for a beginner, but it is VERY important. It tells you what is de fide teaching, or what is binding for all faithful Christians to believe.)
-Aquinas by Ed Feser
-The Last Superstition by Ed Feser
-The Essential Catholic Survival Guide
-Catholicism and Fundamentalism by Karl Keating
-A Biblical Defense of Catholicism by Dave Armstrong
It is important to get your theology and Church teaching squared away. Trust me, I had to learn the hard way. Because I did not understand my faith well enough, I was not able to discern that the objections of atheists/non-Christians were all strawman that did not apply to Catholicism. Lesson: before you start doing contra Protestantism or contra atheism apologetics, learn about your own faith.
If you ever want to talk or get more suggestions, I am just a PM away!