I am RC and went to RC primary school in Ireland, and my DCs went to RC elementary school in the US. My DCs and I went to state schools for secondary (in US this means completely secular, in Ireland relatively secular - school was 'multidenominational').
Nobody in the school will ever address the topic of divorce/remarriage. That is a huge hot potato and would only ever be approached in a full on theology class at secondary or third level.
Science will be taught, and do not worry about evolution. The RC church likes science and has never had a problem with evolution, unlike protestant fundamentalist churches.
Adam and Eve will not be be taught as gospel truth. The RC church is 'prima scriptura' not 'sola scriptura'. Actually, in all the years of seeing my children off to school and supervising homework, I never once encountered any reference to Adam and Eve. Noah's Ark ditto. The focus was on the Eucharist, which is the central element of religious practice, and on what Jesus said and did - parables, teachings, death and resurrection. The emphasis in their religion classes was that we are all God's family, God loves us all, we should try to love one another. During the years of sacramental prep they covered first communion (2nd grade) and reconciliation (4th grade) prep in school - confirmation was done in evening classes.
They did one art unit where they portrayed themselves as saints in the style of certain eras in art. They could pick a saint if they wished for their "dress up as someone famous and give a three minute talk to the class about yourself" day in 3rd grade. DD3 chose Joan of Arc because she liked her warlike qualities...
They had an age appropriate classroom prayer every morning, with any child who wanted to asking for the class to pray for (for instance) a grandfather in hospital, a cat on her last legs, neighbour whose daughter's house was burgled, etc. They had grace before lunch, and a thanksgiving prayer afterwards. At 3 o'clock they had a prayer of thanks for the day. Once a month they had an all school Mass. There is a new priest in the parish now, and Mass is once a week. Children who were not RC could either sit in their pew or go up at communion time with arms folded across their chest and receive a blessing. DD4's Baptist bff used to do that and still does in the very good RC private high school she now attends.
I have a niece who is a Buddhist, attending a RC convent school - no problems related to arrangements for sitting out Confirmation classwork, etc.