I can understand you being nervous. Not everyone is used to standing up in front of a lot of people and saying anything.
You will say a profession of faith; it is normally very short, such as “I profess and accept everything which the Catholic Church teaches and professes”, or something very similar.
Having been involved in RCIA for 25 years or so, we have given the candidates a “cheat card” - a file card, with that written out for them, so they don’t have a brain freeze. We ask them (as there usually is more than one candidate) to do it together. That prevents each one feeling they are “in the spotlight”, and might even be loud enough with the combination of them to allow the first row or two in the pews to hear it.
Seriously, unless someone has had experience speaking in front of a group, or is particularly self assured, most have appeared to have at least a bit of stage fright. No one is going to bite! Don’t panic (easily said, I understand).
Assuming none of the Old Testament readings are omitted, and no one is rushing things, it takes our parish an average of 2 1/2 hours; and we have a reception for those entering the Church afterwards. So a long evening.
God bless you on your journey of faith!