The first year is the hardest version of this you will ever do. The routines aren't set, the wounds are fresh, and every small decision feels like precedent. It gets more ordinary. Here is what helps it get there faster.
Handover time and place, who buys what, how schedule changes are asked for. Every default you set is a hundred future negotiations you don't have.
First birthdays, first Christmas, first holidays apart — they are hard for everyone, the first time. Plan them early and in writing, while everyone is calm.
Keep the practical communication in one place, in one tone, whatever else is happening. When everything else is moving, one boring, reliable thread about pickups is an anchor — for you and for the record.
They will say confusing things about the other house. Mostly it means nothing. React to patterns, not sentences.
The single most useful co-parenting skill in year one is noticing you are running on empty before your child does.
One channel, one calendar, one record — and the daily card each morning so the week doesn't have to be held in your head.