Are you both in same school district where the child can ride bus home to each of you (usually districts will allow two buses in custody situations especially if you get it written in a
court order)?
Few different options and really depends on the child. You can do one week on, one week off (if child needs to see other parent, can have a midweek dinner visit on off week).
Some people do 3/4/4/3 or variations. It really is up to your work schedules, siblings at each house, and how the child reacts. You can try something now and tweek it as you go through the process.
Homework- Have child leave school folder in bag for each parent to see notices without taking them out. Or ask teacher for two copies to put in his mailbox and you can take your own. Have the school office have both addresses and they will send anything form them to both houses. Keep teacher in loop and have conferences together.
Look up 50/50 custody on here and you should get a few old posts about some of the ways people here have done it in the past. It is great you are working together , Good luck!