I'm getting confused

The cantor for the church asked which songs we want to be solos. At first, I didn't really know what she meant. She said that she meant the songs that the congregation will be singing w/ the cantor vs. the songs that the cantor will sing by him/herself.

Ok, I got that... sort of.. at my church...everyone is invited to join in with the chorus of all the main songs. I told her that is why I am confused, and she said a wedding mass is different than a church mass, and I guess the congregation usually doesn't sing?

So I need to figure out which songs the congregation will join in and which ones they wont I guess? IDK why I am so confused, but I guess maybe because I'm not used to it? I know there's a decent number of people on my side who are devout Catholics and WILL sing with the choruses. Am I just supposed to tell them not to sing?

Has anyone else had this situation lol? Any input?