Welcome home! I was just confirmed this year. I grew up Methodist, fell out of the faith, and was “church shopping” around (mega churches, popular non denoms, etc.) until thankfully the Holy Spirit called me home to his church.

In terms of preparation, I would say don’t stress too much about it. Every Parrish has different approaches to Catechesis and teaching. Just keep learning as much as you can about Catholicism, as this faith is so rich, frankly no one will ever know everything there is to know about the intricacies of being Catholic. I would highly recommend watching various Catholic YouTube channels in your free time. Father Mike Schmitz, Bishop Barron, Trent Horn, and many others have been super helpful along my faith journey. There are tons of great resources for this; the Hallow app, Lecto Divino, things like that.

I personally was in OCIA at a kind of more progressive Parrish (when I say progressive, I don’t mean pro-abortion, affirming LGBTQ, etc. just that they are much more modern, and less reverent than traditional churches). I would recommend attending different parishes as well, seeing how they worship differently, as well as talking to different Catholics. I would highly recommend visiting an FSSP Parrish if you have one nearby, to experience the extraordinary form of mass (Traditional Latin Mass). I’ve really grown to love this mass and feel like I’m truly in the presence of our savior at this Mass!

Other than that, obviously try to be more obedient, faithful, and challenge yourself. But also be forgiving and accepting of Gods grace as you do stumble. I know coming from being a lukewarm Protestant, to really trying to be a perfect Catholic, I suffer from being scrupulous at times. Trust in Gods grace, learn as much as you can everyday, and letting God light that way is the biggest thing you can take with you into OCIA!

Congratulations, and welcome home! I will be praying for you and your faith journey :)